Petrel 2010 Reservoir Engineering Course

8/16/2019 Petrel 2010 Reservoir Engineering Course

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Reservoir EngineeringCourse

Petrel 2010



About Petrel*

Development on Petrel seismic-to-simulation software began in 1996

in an attempt to combat the growing trend of increasingly specialized

geoscientists working in increasing isolation. The result was anintegrated workflow tool that allows E&P companies to think critically

and creatively about their reservoir modeling procedures and enables

specialized geoscientists to work together seamlessly. With the

enhanced geophysical tools and the integration of ECLIPSE* reservoir

simulation software and streamline simulation, Petrel is now a

complete seismic-to-simulation application for

• 3D visualization

• 3D mapping

• 3D and 2D seismic interpretation• well correlation

• 3D grid design for geology and reservoir simulation

• depth conversion

• 3D reservoir modeling

• 3D well design

• upscaling

• volume calculation

• plotting

• post processing• streamline simulation

• ECLIPSE



Copyright Notice

© 2010 Schlumberger. All rights reserved.

No part of this manual may be reproduced, stored in a retrieval system,

or translated in any form or by any means, electronic or mechanical,

including photocopying and recording, without the prior written

permission of Schlumberger Information Solutions, 5599 San Felipe,

Suite 1700, Houston, TX 77056-2722.

Disclaimer

Use of this product is governed by the License Agreement.

Schlumberger makes no warranties, express, implied, or statutory, with

respect to the product described herein and disclaims without limitation

any warranties of merchantability or fitness for a particular purpose.

Schlumberger reserves the right to revise the information in this manual

at any time without notice.

Trademark Information

*Mark of Schlumberger. Certain other products and product names are

trademarks or registered trademarks of their respective companies or

organizations.





Reservoir Engineering Table of Contents • 5

Table of ContentsAbout Petrel* ...........................................................................2

Copyright Notice .......................................................................3

Disclaimer .................................................................................3Trademark Information .............................................................3

Module 1 - Introduction ..........................................................11Prerequisites ...........................................................................11

Learning Objectives ................................................................11

What you will need ................................................................12

What to expect .......................................................................12

Icons .......................................................................................13

Terminology ............................................................................14

Workflow diagram ..................................................................19Agenda ...................................................................................19

One application, seismic to simulation ..................................20

Module 2 - The Petrel User Interface ..................................23Introduction ............................................................................23

Lesson 1 – The Petrel user interface .....................................24

The Petrel user interface ........................................................25

Starting Petrel ........................................................................40

Petrel Interface .......................................................................41

Display window ......................................................................42Object settings .......................................................................43

Lesson 2 – Making a simple grid with simulation fault ........47

Exercises - Making a simple grid a with simulation fault .....59

Making a simple grid ..............................................................59

Summary .................................................................................64

Module 3 - Functions ..............................................................65Introduction ............................................................................65

Lesson 1 - Make fluid model ..................................................66

Exercises - Make fluid model .................................................81Make a black oil model from correlations .............................81

Reviewing fluid model settings ..............................................83

Import a keyword fluid model .................................................83

Plotting the fluid model ..........................................................83

Create multiple viewports – Optional ....................................85



6 • Table of Contents Reservoir Engineering

Lesson 2 - Make rock physics functions ................................88

Rock compaction function ......................................................89

Saturation function .................................................................91

Capillary pressure ...................................................................95

Exercises – Make rock physics functions ..............................98

Make a saturation function ....................................................98

Make a rock compaction function ........................................100

Reviewing rock physics functions data ................................102

Import a keyword rock physics function ...............................104

Summary ...............................................................................105

Module 4 - Initialize the Model and View 3DProperties................................................................................107

Introduction ..........................................................................107Lesson 1 – Initialization of the model ..................................108

Introduction ..........................................................................108

Exercises – Initialization of the model .................................120

Exercise Workflow ................................................................120

Exercise Data ........................................................................120

Initialize model .....................................................................120

Lesson 2 – 3D Viewing .........................................................123

Exercises – Results viewing .................................................129

3D viewing ............................................................................129

Making filters using a Histogram window ...........................131View data on an intersection plane .....................................133

Optional Exercise - The multi-value probe ...........................134

Summary ...............................................................................135

Module 5 - Upscaling............................................................137Introduction ..........................................................................137

Lesson 1 – Grid Coarsening using the Pillar gridding

process .................................................................................138

Pillar Gridding - Concept ......................................................140

Pillar Gridding - Terminology ................................................141Exercises – Grid coarsening .................................................148

Grid coarsening using the Pillar gridding process ...............148

Changing the grid orientation ..............................................151

Lesson 2 – Vertical coarsening –the Scale up structure

process .................................................................................153

Exercises – Vertical coarsening and grid quality check .......159




The Scale up structure process ............................................159

Grid quality check .................................................................160

Using value filter ..................................................................162

Averaging methods ..............................................................167

Directional averaging methods for permeability .................169

Exercises – Scale up properties ...........................................170

Exercise Workflow ................................................................171

Exercise Data ........................................................................171

Scale up properties ..............................................................171

Apply different methods .......................................................173

Review the upscaled properties ...........................................174

Review upscaled properties in a 3D window ......................175

Summary ...............................................................................177

Module 6 - Local grid refinements and Aquifers .............179Introduction ..........................................................................179

Lesson 1– Local grid refinements ........................................180

Exercises– Local grid refinements .......................................190

Import a polygon ...................................................................190

Make a local grid set ............................................................190

Inspect the local grid set ......................................................192

Upscale property – Optional ................................................193

Lesson 2 – Aquifers ..............................................................195

Exercises – Aquifers .............................................................202Add an aquifer ......................................................................203

Summary ...............................................................................206

Module 7 - History development strategies .....................207Introduction ..........................................................................207

Lesson 1 – History development strategies .........................208

Exercises - Make a history development strategy ...............217

Import observed data ...........................................................217

Make a history development strategy .................................220

View the development strategy data ...................................221Add a rule to limit the production pressures .......................222

Define and run simulation cases ..........................................223

Exercise: Change the line style in function windows ..........236

Plot window ..........................................................................238

Summary data in a 3D window - Optional ...........................240

View data on streamlines - Optional ...................................241



8 • Table of Contents Reservoir Engineering

Lesson 3 (Optional) – History match analysis .....................242

Exercises – History match analysis ......................................256

Run history match analysis ..................................................256

View match data in a map window .....................................257

View match data in a function window ...............................259

Compare cases in a Map window ........................................260

Summary ...............................................................................262

Module 8 - Well Engineering ..............................................263Introduction ..........................................................................263

Lesson 1 – Import and Design Well Paths ...........................264

Well path design ..................................................................267

Simple vertical well ..............................................................268

Exercises – Import well data and design well paths ...........276Import well data ...................................................................276

Make a vertical well .............................................................278

Setting up the 3D window ...................................................279

Well path design ..................................................................282

Reference project tool ..........................................................285

Lesson 2(Optional) – Automatic well placement .................286

Create best fit well ...............................................................286

Laterals design .....................................................................288

Exercises – Automatic well placement - optional ...............291

Lesson 3 – Results, reports and quality checking ................295Well manager and saved searches ......................................303

Well tops and well report ....................................................304

Lesson 5 – Well completion design .....................................306

Exercises – Well completion design ....................................322

Import well completion events .............................................328

Make completions using the Operations tab .......................331

Summary ...............................................................................334

Module 9 - Prediction strategies ........................................335

Introduction ..........................................................................335Lesson 1 - Prediction development strategy ........................336

Exercises – Prediction strategies .........................................347

Use a default strategy ..........................................................347

Add a new rule to an existing strategy ................................349

Define a prediction case .......................................................350

View simulation results ........................................................351




Make a strategy with a tabular rule - Optional ...................352

Lesson 2 – Keyword editor ...................................................355

Import existing simulation case ...........................................363

Examples of use of the Keyword editor ...............................367

Exercises –Keyword editor - import a case .........................368

Load a simulation case ........................................................369

Edit the case .........................................................................370

Run the simulation case .......................................................371

Convert to Petrel case ..........................................................372

Summary ...............................................................................373

Appendix 1 - Advanced Workflows ...................................375Dual porosity – Dual permeability .......................................375

Sector modeling ...................................................................377Hysteresis .............................................................................380

Remote job submission ........................................................382

Index ........................................................................................383





Reservoir Engineering Introduction • 11

Module 1 - Introduction

The purpose of this course is to introduce you to the reservoir

engineering tools in Petrel. In this course, you will create a simple

simulation grid and upscale a geological grid. You will learn how to

create black oil fluid tables and rock physics functions in Petrel. In

addition, you will import and design wells and add completion items.

Finally, you will combine it all and submit it for simulation before

viewing results inside Petrel.

Traditionally, the engineer had to employ a range of different softwaretools, hence, data had to be exported/imported between the different

applications. Also, feedback to the geological model used to be difficult

to implement. The vision for Petrel RE is to make all of these tools

available from the Petrel user interface.

Prerequisites

To successfully complete this course, the user must have knowledge of

the following:

• English proficiency• Basic Windows and practical computing skills

• Familiarity with reservoir engineering fundamentals

Learning Objectives

In this course, you will prepare black oil simulation cases for ECLIPSE*

and FrontSim* using Petrel. You will learn:

• About the Petrel user interface

• How to build a simulation grid

• How to scale up structure and properties

• How to use the correlation library to make black oil fluid tables

and rock physics functions

• How to use the well engineering tools in Petrel

• How to set up simulation cases and view the results



12 • Introduction Reservoir Engineering

What you will need

In this course, you will need the following hardware and applications in

order to perform the workflow:

• A personal computer with a minimum of 2GB of RAM; however,we recommend 16GB of RAM for optimal performance.

• For Petrel 32-bit: Microsoft XP 32. For Petrel 64-bit: Vista 64 and

XP 64.

• A graphic card compatible with Petrel

• A Petrel license and license key

• Petrel Seismic to Simulation Software with the latest updates

• Training datasets

What to expectIn this training material, you will encounter the following:

• Overview of each module

• Prerequisites to the module (if necessary)

• Learning objectives

• A workflow component

• Lesson(s)

• Scenario-based exercises

• You will also encounter notes, tips and best practices




Icons

Throughout this manual, you will find icons in the margin representing

various kinds of information. These icons serve as at-a-glance

reminders of their associated text. See below for descriptions of whateach icon means.

Tips

This icon points you to a tip

that will make your work

easier.

Notes

This icon indicates that the

following information is

particularly important.

Best Practices

This icon indicates the best

way to perform a given

task when different options

Procedures

This icon identifies the

steps required to perform a

given task.

Exercise

This icon indicates that it’s

your turn to practice the

procedure.

Warnings

This icon indicates when

you need to proceed with

extreme caution.

Questions


questions at the end of

each lesson.

Lessons

This icon identifies a

lesson, which covers a

particular topic.

Review Questions


review questions at the

end of each module.

Prerequisites

This icon identifies any

prerequisites that are

required for the course, or

for individual modules.

Learning Objectives


learning objectives set out

for the course, or for the

current module.

What you will need

This icon indicates any

applications, hardware,

datasets, or other material

re uired for the course.


prerequisites that are

required for the course, or

for individual modules.


learning objective set out

for the course, or for the

current module.


applications, hardware,

datasets, or other material

required for the course.




Terminology

Petrel introduces new terms and expressions. Some of the most

frequently used in this manual are briefly explained below.

3D Grid - A network of horizontal and vertical lines used to describe athree dimensional geological model. Petrel uses the “Corner Point 3D

Grid” technique.

Boundary for the Pillar grid – Defines the extent of the model. You

can use a polygon as input, or you can digitize the boundary. Faults can

be set as part of the boundary.

Cases pane - Shows volumetric cases and simulations cases as set up

in the “Define simulation case” process.

Cell - The smallest volumetric element in the Pillar grid. Each cell has aunique I, J, K position in the Pillar Grid. I, J, K positions are zero based

integer locations of cells in a grid. It uses a left-handed orientation I, J

being a horizontal surface and with K increasing downward. The grid

has a number of cells equal to the number of I times the number of J

times the number of K points. I, J, K indexing provides a way of

identifying a cells position in the grid.

Contact level - The level of a Gas-Oil contact or an Oil-Water contact,

normally at a constant depth but a tilted contact can be represented by

a surface.

Corner point grid - A flexible grid structure where the eight corners of

a cell (the nodes) can be moved to form irregular cell geometries.

Directions (in the Pillar gridding process) – User defined guidance for

orientation of cells along faults. A fault can be given a direction in

which case the grid is enforced to be aligned with that fault.

Fault - Vertical surface that segments the Pillar grid. It is represented

by a set of pillars that join together to define the fault. An area

enclosed by faults will, by default, make out a segment of the model. A

fault can be given a direction in which case the grid is enforced to bealigned with that fault.

Filter – Petrel can display the whole model (all elements) or selected

parts of it. Powerful filter techniques enable the user to take full control

of the 3D grid and visualize only the elements of interest for quality

control. Filters in Petrel are used both for visualization and for




calculations. There are two basic types of filters in Petrel. The first type

is a simple On/Off type, where an element is either turned on or off.

Other filters are more advanced (for example filtering of properties) and

are based on values set by the user.

Function bar - Also called tool bar (in Microsoft terminology). This is a

group of icons on a horizontal or vertical bar. Only icons that can be

used with the current active process is displayed in the function bar.

Function window - Plot window used to display functions, cross

plots, sample variograms and variogram models.

Histogram window - Plot window used for display of histograms and

cumulative distribution functions.

Horizon - The equivalent of a surface, except that a horizon is a surface

in a 3D grid and an integrated part of the 3D model. A horizon in a

Petrel 3D grid can have multiple Z values at a single XY value whereas

a surface can not.

Input pane - imported data such as lines, wells, fluid models, gridded

surfaces and SEG-Y data is stored here. Also data created by Petrel

process like: Development strategy, Rock physics functions, etc.

Intersection - A cut through a three dimensional model (3D grid).

Intersections can be plane surfaces with arbitrary direction and dip, but

can also be cross sections along one of the main directions of a 3D grid(I, J, K directions).

Intersection window - Plot window used for generation of scaled

plots of cross sections.

Editor - Allows you to use all functionality of ECLIPSE and FrontSim,

which can not be accessed through the Petrel user interface.

Layers - Fine scale division of 3D grid, which defines the cell thickness.

LGR - Local grid refinement; allows for a finer resolution of the grid in

demanding areas. Local grids are defined using wells, surfaces andpolygons as input.

Map window - Plot window used for generation of scaled plots (2D

maps), and for display of history match values and variogram maps

created in Petrel.

Menu bar - Special tool bar at the top of the screen that contains




menus such as File, Edit, and View.

Model - Complete set of data needed to describe a three dimensional

geological model. This includes the 3D grid structure with faults and

horizons, and all cells with different properties. Each project cancontain several models and each model can contain several 3D grids.

Models pane - data connected with a 3D model (such as faults, trends

and 3D grids) is stored here. Velocity models and discrete fracture

network models are also stored here.

Nodes - In a 3D grid, nodes are corner points of the grid cell. In a 2D

grid they are intersection points between grid lines.

Pillar gridding - The process of creating the three-dimensional (3D)

grid. With this process you make the framework of the 3D grid using a

combination of key pillars, trend lines and a boundary. The result is a

three dimensional framework called a skeleton grid.

Pillars – Vertical lines connecting the corner points of 3D grid cells.

The shape can be any of the four standards: vertical, straight, listric or

curved. There are two basic types of pillars in a 3D grid: faulted and

non-faulted. After the pillar gridding process, the key pillars are

replaced with faulted pillars. Non-faulted pillars are inserted in the non-

faulted area of the 3D grid.

Polygon - Polygons made in Petrel can be used for many differentpurposes. Like digitize contours for structure maps, isochores or

properties. Boundary polygons are used in the “Make surface” process,

or as a boundary in the “Pillar gridding” process or the Make aquifer

process.

Processes pane - All the processes that you can apply to you data is

located here. For each Process a new set of tools is available in the

Function bar.

Results pane - the numerical results of volume calculations and

simulations are stored in this pane, such that they can be visualized andany reports made. Also Observed data for Development strategy is

stored here.

Segments (Regions) – Segment in Petrel is an area that is closed by

faults, grid boundary, segment boundaries or any combination of these.

Segment is similar to the term “Regions” used in ECLIPSE.




Simulation grid - The 3D grid that will be used for flow simulation in

Petrel or exported to other simulation packages. This grid is usually a

coarser, upscaled version of the geological grid.

Skeleton – Three 2D grids representing the top middle and base pointsof the Key pillars in a pillar grid. These are used to quality check the

pillars and therefore the 3D grid. The skeleton is not related to horizons

in the grid in any way.

Status bar - Information on processes, coordinates, etc. in the right-

bottom corner of the user interface.

Surfaces - 2D grids (imported or generated in Petrel). A surface is a

simpler version of a horizon in Petrel, the major difference being that

horizons are held in 3D grids (as opposed to 2D grids) and can therefore

have multiple Z values at each XY point. Surfaces are stored in theInput pane, while horizons are stored in the Models pane.

Templates - Are linked to objects in Petrel and control globally their

settings for color, units, measurements etc. Petrel comes with several

predefined templates: depth and thickness color tables, property

templates and seismic color tables.

Templates pane - color tables and all the different templates are

stored under this pane.

Title bar - The file name (project name) and location is displayed in theTitle bar on top of the user interface.

Tool bar - Icons for commonly accessed commands in the user

interface. These tools are useful shortcuts for items that also can be

found by accessing the menu bar.

Transmissibility multiplier – The transmissibility is a number

assigned to cell faces that describes the ability for a fluid to flow from

one cell to another. A transmissibility multiplier can be assigned to

faults to change the ability for a fluid to flow past the fault.

Trends (in the Pillar gridding process)– User defined guidance for thegrid cells orientation in a particular direction (I- and J-directions). Also

segment divider (when no faults).

Weighting – Used in several processes to increase or decrease the

importance of some of the data in a computation. For example, in the

Scale up properties process one can decrease the influence of property




values from cells with a tiny volume when populating the coarse grid by

using the Volume weighting option.

Well tops – Intersection points between well trajectories and

structural surfaces. Sometimes called well points, well picks or tiepoints.

Well trajectories - Lines in space representing well paths.

Well section window - Plot window used for display of well sections

used in the Well correlation and the Well completion design processes.

Windows pane - stores all opened and active plots and windows used

in the Petrel project. In addition it holds the Light sources and the

Cursor tracker.

Workflows pane - stores workflows made using the Workflow editorand/or the Uncertainty and optimization process. In addition it holds a

folder with predefined variables.

Zones - A zone is defined by the volume between a top and a bottom

horizon.




Workflow diagram

Agenda




One application, seismic to simulation

Usability

Familiar

windows style

Tools from

seismic to

simulation

Petrel 2010




Traditionally, the geoscientists provided input to the reservoir

simulation model. Since Petrel provides one tool for the entire

workflow, it is easier for the different professionals to work in an

interrelated way.

The building and maintaining of a simulation model is an iterative

process. As the tools for modeling and simulation are available in one

single application, it is easier for the engineer and the geologist to

cooperate.

The engineer used to depend on a number of software products in order

to set up, run and view the results of a simulation.

Petrel now provides one common user interface for workflows from

seismic interpretation to reservoir simulation.




The vision of Petrel is to incorporate all of those tools into one common

user interface to avoid challenges and time spent on import/export.

Most of the major workflows in ECLIPSE Office, Schedule, FloGrid, and

FloViz can be accomplished in Petrel 2010.1, but there are still some

gaps.

The main gaps are:

• FloGrid – Petrel has no unstructured grids; no upgridding (the

workflow to determine where to put the layers based on

property distribution).

• Schedule – On import, Petrel extracts data from the WELSPECS

and COMPDAT keywords together with dates. But it will not

make any Development strategies. In Petrel, layer shifting is

accomplished by correcting the grid to match the well tops,

rather than moving perforations to match a bad grid.

• Compositional fluid properties – Petrel offers functionality to

make compositional and thermal PVT models. However, the

equation of state (EOS) of such models cannot be tuned to the

laboratory experiments.



Reservoir Engineering The Petrel User Interface • 23

Module 2 - The Petrel UserInterface

Introduction

In this module, you will become familiar with the Petrel user interface.

You will also learn how to make a grid using the Make simple grid

process. This is a process that can be used to make grids for non-

faulted reservoirs. However, it is possible to insert a “simulation fault”

into the grid to model the effect of a (partially) sealing fault.

Prerequisites• There are no prerequisites for this module

Learning Objectives

In this module, you will learn how to:

• Start Petrel with a new or an existing project

• Navigate in the user interface

• Review and alter settings for Petrel objects• Display data in 2D, 3D, and function windows

• Make a simple grid for a non-faulted reservoir

• Insert a simulation fault into the simple grid



24 • The Petrel User Interface Reservoir Engineering

Lesson 1 – The Petrel user interface

Petrel RE for newcomers

Menus Settings Visualization File management




User interface

Tool bar

F u n c t i o n

b a r

Petrel

explorer

panes

Display

window

Menu bar

Object informationStatus bar

The Petrel user interface

The Petrel user interface consists of two main windows, the display

window and the Petrel explorer panes:

Petrel explorer panes: There are eight panes available in Petrel and they

can be put in two separate explorer windows (default). All panes have

free placement and grouping, and can be enabled or disabled from the

View option in the Menu bar.

The Input pane contains all data that is not defined as part of a 3D grid

or a fault model. The Models pane contains all fault models and 3D

grids with grid properties.The Templates pane contains predefined templates, while the Results

pane is a filter for simulation and volumetric results.

The Processes pane contains a list of the available processes in Petrel

in the order which they are usually performed. The Workflows pane

contains workflows created by the Workflow editor or the




Uncertainty and Optimization process. The Cases pane stores all

simulation and volumetric cases and the Windows pane stores all

windows (3D window, interpretation window etc.).

• Toolbar: General tools related to import and visualization• Menu bar: Familiar Windows menus, such as File > Open, Edit

> Copy, File > Save, Help > Manual.

• Function bar: Tools related to the selected process in the

Processes pane.

• Object Information: When clicking on an object in the display

window, information about it will appear in the lower right

corner.

• Status bar: Shows the status of the last performed action.

Input and Model panes

Input pane

Contains all imported data

and all subjects that are

not a part of the 3D grid.

Models pane

Contains all Fault models

and 3D grids.

Bold item

Click on an object name to

make it active.

Input and Model panesBold Item: Note that the name of the active item is printed in a bold

font. It is the active item that Petrel will use in a process. For instance,

if you want to use the Top Tarbert data as input for making a surface,

select it by clicking on it, it becomes bold and Petrel recognizes this as

the object to use and you know which item is active.




+/- Sign: Data is stored in folders within the Petrel explorer panes. The

folders are expanded by clicking on the plus sign and collapsed by

clicking on the minus sign in front of it.

Cases and Results panes

Cases pane

A new case is added each time

a simulation or volume case isdefined.

Results pane

Used to select lines to view in

function windows.

Used to display 3D properties

in 3D window.

Cases and Results panes

When a simulation case is defined, it is stored on the Cases pane. Thecheck box in front of the case is used to select to view results from that

particular case. You can plot line vectors (rates, pressures, etc.) in a

function window by specifying which data to view on the Results pane.

The simulation grid results (Static and Dynamic grid properties

computed by the simulator) are also stored on the Results pane. To

visualize it, you can use 3D or 2D window. Use the time player to see

how the properties change during simulation time.




1. Active Process

A process needs to be

active (bold) to be used.

1

Processes paneFunction bar

2. Function Bar

Shows available tools for

the selected process.

2

Only one process can be

active at the time.

Processes pane and Function bar

The Processes pane contains a list of all available processes in Petrel.If a process is available, the process name will be colored black. If a

process is not available, it will be grayed out and you cannot select it.

There are various reasons why a process may not be available. The

most common reason is that a previously required process has not been

completed. For example, you don’t have access to property modeling

before you’ve defined horizons. Another reason is licensing. A red

prohibition sign indicates that your license configuration does not

contain that process.

The Function bar is located on the right hand side of the screen and

contains the icons/tools available for the current active process within

the Processes pane. The available tools are active and in color, this

will help you to know which tools to use for each process.




Workflow editor and the Uncertainty and optimization process:

The Workflows pane stores workflows created by the Workfloweditor and the Uncertainty and optimization process. Workflows

provide a programming-like user interface to Petrel. They allow for

automating tasks such as plotting or sensitivity studies. New workflows

are initiated from the Insert option in the Menu bar. Uncertainty, proxy,

and optimization workflows are made using the Uncertainty andoptimization process which is stored in the Utilities folder of the

Processes pane.

Windows pane

All visualization windows in a project are stored on this pane. Even if

you exit a window, it will still be stored in the Windows pane. Use the

Windows pane to organize windows. You can, for example, delete

windows and rename windows for quick access. When plotting the oil

production rate, rename the Function window to Field oil production to

better distinguish it. A checked box in front of a window indicates an“open” window. Having many open windows can slow down

performance, thus, it is recommended you keep the number of open

windows to a minimum. Each window is stored as a folder in the

Windows pane. In this folder, icons are stored which are used for

visualizing legend, axis, setting background color, etc. Those tools are

also found in the toolbar.




Coordinate systems

Petrel offers the possibility to do

cartographic transformations of

data on export and import.

With 2010, only some data

types are supported, mainly

lattice data such as 3D seismic.

Select Null to disable this

functionality.

Petrel 2010.1 is the first release that offers the possibility of doing

cartographic transforms and conversions on import and export. Well

data is supported, but not 3D grids, hence, it is not yet fully functionalfor reservoir engineering purposes. Select Null, to disable the

functionality and to make Petrel perform like pre-Petrel 2010.1.




Note: There is NO unit conversion insidePetrel; it has to be done on import.

Units

Select a Unit system from the drop-

down menu (e.g. Metric or Field), or

select Customize to set units from amixed unit system.

Project settings and units

Project settings

Petrel will allow for a mix of different units to be imported into the

project. A typical example is to have well data and production data in

feet, and maps and other data derived from seismic in meters. You must

check to ensure that the data is imported with the correct units. It is

not possible to convert units of data already imported into the project,

but data can be converted on import and export.

The best workflow to ensure common units in a Petrel project is:

1. Check your data before import and decide which units are best

to use as your project units. Petrel will allow you to use local

coordinates, field, metric or a combination, which most

commonly are UTM coordinates in the XY-direction and feet in

the Z-direction.

2. When creating a new Petrel project, open the Project settings

as described on the slide and select the unit system you want

to use in your project.




3. For every object you import, check the file before import to

inspect the units of the data. Then, select to apply unit

conversion in the import dialog, if needed.

4. If you discover that the unit of a data object is inconsistent

with the other data in the project, delete it and re-import it

with the correct conversion.

When importing data from ECLIPSE keywords, Petrel is looking for

METRIC or FIELD keywords in the file. If none of this is specified then it

will assume that the data in the import file is in the same unit system

as Petrel project. If it is specified, and the units of the file you import is

different from the units in the project, then the data will be converted

on import.

Also note that Petrel has two different concepts of time units; namely

depth measured as two way traveling time for the seismic waves in

addition to the usual meaning of time.

1. Every object has a

settings window

1

Object Settings

2. Access settings

2




Object settings

To access the settings dialog for objects in Petrel, right-click on the

object and choose Settings, or double-click the object.

The Settings dialog provides information about the object and whetherit is possible to alter the objects. The tabs vary by the object type.

Most objects have a Style

tab. Possible to adjust display

parameters.

Object SettingsStyle tab

Style tab

The Settings dialog contains different tabs and information. Depending

on the type of object, additional tabs will be added for more

functionality. However, the settings will always include an Info tab and

a Statistics tab. The Style tab is only active when a display window

related to the Style options is active (for example, 2D vs. 3D displaywindows).




Object SettingsInfo Tab

1. Rename objects by entering a

new name.1

2

2. The Template can be

changed.

3,4

3. The Comments tab is empty

by default; designed for user

input.

4. The History tab keeps track

of the main events related to the

object (e.g. operations, dates

etc.).

Info tab

On the Info tab, you can rename the object and change the template.

The Comments tab is a white, editable area where you can add any

information such as the source of the data that was imported and its

reliability.

The history of the object is stored on the History tab, including

information about edits and operations performed on the object. By

right-clicking in this field, you can add your own date stamped

comments or clear the history completely. Note that not all objects have

a History tab.




Object SettingsStatistics Tab

The content of each item can be checked

under the Statistics tab. The zones can beviewed separately.

Lists

The first list gives the X, Y, Z coordinates. If an

attribute is available it will also be shown.

One or all lists can be copied to an output

sheet. Toggle on one of the lists (e.g. List 1)

and click the output icon. The contents of the

list will be written to an output window.

Statistics tab

It is important to quality check (QC) the statistics for accuracy to verify

that the items hold the correct values.

By default, ‘Z’ values are negative based on a reservoir being below sea

level. If your data is above sea level, select the appropriate options

when importing your data. Remember that this is opposite from

GeoFrame which works in positive ‘Z’ values.

It is possible to generate a report from the statistics table: Click on the

Copy to output sheet button. A report will be generated and it can be

saved to file or copied and pasted into Excel.




Visualization

Windows

Visualization windows

A range of different types of windows are available:

• 3D window – for visualization of data in 3D.

• 2D window – for visualization of data in 2D. This is useful

when working with polygons, and when you want to be certain

that you are viewing from above.

• Map window – Used for plotting horizons and layers of the 3D

property.

• Intersection window – plotting window for intersections.• Interpretation window – 2D window used for seismic

interpretation.

• Histogram window – used for plotting histograms.

• Function window – used for plotting cross plots, variogram,

and line plots.

• Stereonet window – used for displaying dip and azimuth data.




• Well section window – used for well correlation, interpreting

logs, and defining well bore completions.

• Plot window – Multiple viewports can be inserted (for

example, function, intersection, and histograms together). A

viewport is a limited rectangular area where data objects are

displayed.

• Tornado plot window – to display an organized overview of

analysis results.

VisualizationDisplay tools

Maneuvering from Function bar

Select/Pick mode – Allows for

selecting objects and getting

information about them (in the

status bar)

Visualization from Tool bar

Move – Left mouse button

View all displayed data

View from specified position

Target zoom

To move the view in any of the windows, use the left mouse button.

However, to be able to move anything, you must have the View mode (hand) active. When the View mode is active, a hand is shown instead

of the mouse pointer.

The Select/pick mode (arrow) is used to select an item. When in this

mode, you can click on any object and get information about it in

Petrel’s lower right corner.




Note that all windows that show a vertical scale can be set to show

data in either TWT (two way time) or TVD (true vertical depth). The

default is Any, which means that data from different domains can be

mixed in the windows (for example, useful for checking whether the

wells are intersecting with the seismic data cube). However, if the

vertical scale of a window is set to TWT, it is not possible to view depth

data in the window. If you ever have trouble visualizing data in the

selected window, always check that the vertical scale of the window is

set to TVD (or Any).

VisualizationCheck boxes

Gray, square boxes – select the

check box to display the object in the

active window. Several objects can be

displayed simultaneously.

Gray, radio buttons –only ONE object

at a time can be displayed.

Yellow, square boxes – Filters. Used

to filter out different parts of a 3D grid.




Opening and Saving Petrel Projects

1. Open Project:

Opens an already saved Petrel

project (.pet). 1

1

2. Save Project As:

Saves the Petrel project,

prompting you for a new name.

The .pet file, the .ptd data

folder, and the .sim folder are

saved.

2

3. Automatic Save:

Automatically saves the Petrel

project, overwriting the current

saved version. Should be used

with caution.

3

Petrel File Management

The .pet file contains the

index of all data in your

project.

Note: When making a backup or sending your project to support,

you must include the two associated directories, not just the .pet

file – all it contains is the index, none of the data!




Petrel File Management

The .sim directory contains a

directory for each case you create,

plus the Cache__ directory for

temporary index files

Each simulation case directory

contains the simulator keyword

input files and result files

Exercises – The Petrel user interface

The following exercises give you a general introduction to Petrel.

Exercise Workflow• Starting Petrel

• Petrel interface• Display windows

• Object settings

• Editing of input data

Exercise Data

In this exercise, we use the project Dataset > Completed_2010.pet.

Starting Petrel

Start the Petrel program by double-clicking on the Petrel icon on

the desktop.If a bitlock is used, an introduction window to Petrel will open before

the Petrel program window opens up. If you are not using a bitlock

(dongle), you will first see a “Net License Modules” dialog asking which

module package you want to run. At your location, you may have

several levels of licenses. You should use the license that has the

functionality you need for the work you are doing.




Exercise steps1. Start Petrel. You can find the data used in this course in a

folder called Dataset. This folder also contains some

completed exercises. These are stored in the 2010 backupprojects folder.

2. Open the training project. Do this by clicking File > Openproject and select the Completed_2010.pet file from the

Dataset directory.

3. Copy the project: Save it to your Student directory by selecting

File > Save as. Give it a new name and click Save.

Online Help Manual

The Online Help Manual is a document that comes with eachinstallation of Petrel. It is the most extensive documentation on Petrel.

You open it by clicking Help in the menu bar.

Petrel Interface

The Petrel user interface is separated into two main window areas.

These are the Petrel explorer panes and the Display window with the

Function bar on the right hand side. The available tools in the Function

bar depend on which process is active. At the top of the Petrel interface

is a standard menu bar and a toolbar.All data that is not connected to a 3D grid is stored on the Input pane.

Examples are wells and well top (well picks), rock physics functions,

and fluid models. Data that belongs to a 3D grid is stored together with

the 3D grid on the Models pane. Examples are, surfaces that are

defined as part of the 3D grid (in Petrel called Horizons), grid properties

such as porosity, and fluid contacts. The simulation grid properties (the

output from simulator, for example, pressure, oil saturation (SOIL)) are

stored in the Results pane.

Exercise steps1. Click on the Input pane. Right-click the Wells folder and

select Expand (recursive) from the menu. The folder with

sub folders is now expanded. Right-click the Wells folder

again, and select Collapse (Recursively).2. Right-click on different folders to see which options are

available. Select Settings from the list. A window providing




access to functions and settings for the selected folder opens

up.

The Processes pane contains a list of all available processes in Petrel.

They are sorted in the order which they are typically performed. Someof the processes can only be run once the process above in the list is

completed. For example, you must create a 3D grid before you can

insert horizons, and you must define a fluid model before you can define

a simulation case. Processes that are grayed out cannot be used until

the process listed above is executed.

Like most PC software, the menu bar has the standard File, Edit, View,

etc. drop-down menus. In addition, on the right hand side of the Petrel

interface there are icons in a toolbar with additional Petrel related

functionality. This toolbar is called the Function bar, and the tools

available depend on which process has been selected in the

Processes pane. All of the icons in the toolbars have a descriptive text

associated with them. The text appears if you move the mouse pointer

over an icon.

Exercise steps1. Click on each of the items in the menu bar to see the tools

available. You may want to experiment with some of the

options.

2. Slowly move the mouse pointer over the icons in the toolbar.

Text will appear describing the function of each icon.

Display window

A variety of windows can be displayed, examples are 3D and 2D

windows, well section windows, function windows (for plotting), and

interpretation windows (for seismic interpretation).

Exercise steps

In this exercise, you will use a 3D window.

1. Open a 3D window by selecting New 3D window from the Windows menu in the menu bar.

2. Display an object from the Input pane by selecting the check

box next to it. Click on the Viewing mode button (at the

top of the function bar) and move your mouse pointer over the

display. A hand should appear instead of the pointer. This

If any of the panesdisappear, go to the View tab

in the Menu bar and select

Panes to reopen them.




means you can manipulate the display.

3. Left-click and move the mouse to rotate the object in 3D.

4. Hold the SHIFT or CTRL key down, left-click, and move the

mouse. This will pan the object. With a three button mouse,

you can use the mouse wheel to pan the object.

5. Hold both the SHIFT and CTRL keys down, left-click, and move

the mouse. This will zoom the object. With a three button

mouse, you can use the left and middle button to zoom.

6. Press the ESC key. The hand now changes back to the regular

mouse pointer. You can also use the Select/pick mode

button to do this (on the Function bar).

7. Click on an item in the display, using the mouse pointer. Note

the information that is displayed in the status bar at the bottom

of the window.

Object settings

Whether you are importing files, building a new project, or reviewing

someone else’s project, the Statistics tab of the object settings

provides you with valuable information.

Exercise steps1. In the Models pane, right-click the 3D grid named Fine grid

and select Settings.

2. Go to the Statistics tab and check the size of the 3D grid. You

can check the minimum and maximum values for X, Y, and Z.

You can also find the number of cells and the average

increment in all spatial dimensions.

3. Go to the Properties folder of the 3D grid, and check the

statistics for a grid property. For instance, check the range of

the permeability or porosity.

4. Check the statistics of the Properties folder or of another file

folder.

The Statistics tab is read-only and is used for information and qualitychecking (QC). To change the appearance of an object, you need to use

the Style and Info tabs.

Exercise steps1. In the Models pane, right-click a property in the Properties

folder under the 3D grid Fine. Select Settings and go to the




Info tab. Note that you can change the name of the property by

entering a new name and clicking Apply. The name of any

object can be changed in its Info tab.

2. From the Info tab, the template can also be changed. Click on

the arrow alongside the template name to see the list of

available templates to choose from.

3. Open a 3D window, and clear it of all items ( Window > Clearall visualizations) and select to view one of the Horizons

under the Fine grid.

4. Right-click the Horizons folder, select Settings, and go to the

Style tab. Here you can specify display options.

5. Open the Grid lines tab and select the check box Show to

view grid lines. Click Apply and observe that you can now

view the grid lines on the horizon.

6. Deselect to view the grid lines, and open the Contour lines

tab instead. Select the check box Show, then click Apply and

observe the changes. You can also specify the thickness and

the color of the contour/grid lines in the Style tab.

7. Select to view the faults in the 3D window along with the

horizon by select the check box in front of the Faults folderunder the 3D grid.

8. Right-click the Faults folder, select Settings and go to the

Edges and intersections style tab. In the Lines sub-tab, you

can select whether to display pillars on the fault. The pillars

define the mesh cell edges in the Z-direction.




Exercise steps1. Right-click the Porosity property under the Properties folder

of the Fine grid, and select Settings. Open the Histogram tab

to view the distribution of values.

2. Similarly, go to the Histogram tab in the Settings of

Permeability. View the distribution of the 3D grid property.

3. Insert a New histogram window from the Window menu.

Select to display the Porosity property from the Fine grid.

You can use function windows to view simulation results. The next

exercise will show you how to select the data for display in a function

window.

All objects have an

Info and a Statistics tab in

the Settings dialog. Some

objects have more tabs. For

3D grid properties, you will

probably find the Histogram

tab useful.




Exercise steps1. Open a New function window.

2. Select vector to view:

a. Go to the Cases pane, and select the case Aquifer.b. Go to the Results pane, and select the check boxes in

front of Oil production rate under the folder Dynamicresults data > Rates.

c. Under the Identifier folder in the Results pane, expand

the Well folder and select P06. Thus, we will only view

results for well P06.

d. Further down in the Results pane, you can find the folder

Source data type. Expand this folder to select which

source data you want to display. Select Observed data.

Now, both simulated and observed data will be displayed.

You should see oil production rate as a function of time for

well P06 in the function window. With the default settings,simulated and observed data are shown as a solid line and

circles respectively.

e. Go to the Cases pane and select Aquifer_RESTART. This

is the simulation case containing the strategy on how to

operate the field in the future, and display prediction for

well P06.




3. Change the display options for the function window:

a. Your function window is stored in the Windows pane.

Expand the folder Function window, and then expand

the Function 1 folder.

b. Turn the Symbol legend and the Header on and off.

c. Right-click Axis, and select Settings. Go to the Ticks tab

to specify the increment in x and y in the function window.

Go to the Annotation tab to change the size and

alignment of x- and y- axes labels.

d. Go to the Plot tab. In the Line style tab, you can change

the thickness of the lines in the Function window.

Lesson 2 – Making a simple grid with simulation

fault




Make simple grid

Make a grid without faults

The Make simple grid process, which is located under Utilities,

makes it easy to create a grid without faults. The geometry of the grid

is defined by the input to the process.

A project boundary can be added, or minimum and maximum values

from x, y, and z can be used.

Surfaces can be inserted to define horizons in the 3D grid




Make simple gridResult

Skeleton A top, mid, and base skeleton

grid is generated. Further

subdivision in the vertical

direction is needed.

If the process is run without using surfaces to define horizons, the result

is a skeleton grid.

A “skeleton grid” is a Petrel term for the framework that is made as thefirst step towards defining a 3D grid. A skeleton grid consists of a top,

mid, and bottom mesh defined by pillars. The pillars define the lateral

position of the corners in the three meshes, and the z-position is

defined as the bottom, mid point, and the top of the pillars. After the

skeleton grid is generated, it needs to be further subdivided in the

vertical direction. This is done by inserting surfaces. The topmost and

the bottommost surface that are inserted define the top and the bottom

of the final 3D grid, hence, the top and the bottom skeleton grid are

usually outside the final 3D grid.

The reason why 3D grids are generated this way in Petrel is that the

gridding process starts with modeling the faults, which are defined

using pillars. Those pillars are then used to define the geometry of the

3D grid. The processes used to make grids based on fault modeling are

Fault modeling and Pillar gridding.




Make simple gridWith Insert Horizons

Skeleton with horizons

If you have surfaces that describe

the horizons, you can enter them

as input.

If you have surface data in the Input pane that describes the horizons,

you can drop them into the Input data tab of the Make simple grid

process. The result will be a skeleton grid with horizons.




Make simple gridVertical subdivision

Make Horizons

Insert a horizon in the grid to

define different zones.

Layering

Further subdivision is done by

employing the Layering process.

Vertical subdivision

The Make horizons, Make zones, and Layering processes are used

to perform further vertical subdivision.

Make Horizons - This process usually defines the main depositional

units of the 3D grid and are, in most cases, the layers identified and

interpreted on seismic data. The Make horizons process samples inputsurfaces into the 3D Grid. Note that a “Horizon” in Petrel is a surface

that is a part of the 3D grid.

Make zones – This process defines the sub-units of the 3D grid. The

process inserts additional horizons (and zones) into the 3D grid by

inserting isochores up or down from the previously input horizons. The

isochores can be gridded thickness maps or calculated directly from

well tops. Zones can also be defined as specific thickness intervals or

percentages of the main zone.

Layering – The final step is to make the final vertical resolution of the

3D grid.

To keep the modeling simple, we will not perform the Make zones

process. That is, we assume that the stratigraphic layering is defined by

the surfaces that we insert. Then we will do layering to obtain a

suitable resolution for simulation.




Make Horizons

1. Append desired number of horizons in the table.

2. Drop in interpretations or surfaces using the blue arrow.

The Make Horizons process

Double-click on the Make horizons process to open its process dialog

and select the Horizon tab. In the table that appears, insert the number

of horizons to be generated.

The Multiple drop option allows you to insert a list of items in one go

into the Input#1 column: Make sure your input horizons are sorted in

the correct stratigraphic order in the Input pane, then select the first

item, and click on the first blue arrow under Input#1. All of the input

horizons will then be inserted in the same order as they appear in the

Input pane. Horizon names are updated according to input names, but

can be overwritten if desired.

Horizon Type:

You should specify whether the horizon is an Erosional, General,

Discontinuous or a Base surface.

• Erosional surfaces will erode surfaces below

• Surfaces above a Base surface will be on lapped to the Base.

• Surfaces above a Discontinuous surface will be on lapped on it

and surfaces below will be truncated by it.

• A general surface will be truncated by any other surface.




Make horizonsResult

The horizons appear in

the Models pane. Select

the check box to view in a

3D window.

Available for displaying:

1. Edges - to see

zone division

2. Zone filter - to

view selected

layers

Make Horizons – Output

Horizons folder – The layers added in the Make horizons and Makezones process will be stored in the Horizons folder.

Fault filter – The fault filter will allow you to visualize the fault throwfor just one horizon at a time and is mainly used for mapping purposes.

Zone filter – A zone in Petrel is defined as the thickness between two

horizons, and is created in either Make horizon or in the Make zones

process. The zone filter allows you to visualize the edges and the I- and

J- intersections of the 3D grid zone by zone. The zone filter is also

applicable for properties when we generate these in the 3D grid.




Layering

1. Specify the Zone division.

2. Specify number of layers (Proportional), cell

thickness (Follow top/Base) or Fractions. Proportional

Follow Base

Follow Top

Fractions

Follow Base

with Reference

The Layering process

After the Make horizons (and the Make zones) process is run, further

layering is inserted by running the Layering process. You can selectfour different ways of doing the layering:

• Proportional: The zone will be divided into Number oflayers, equally thick layers

• Follow base: The zone will be divided into layers with

thickness Cell thickness, starting to build from the horizon

below.

• Follow top: The zone will be divided into layers with thickness

Cell thickness, starting to build from the horizon above.

• Fractions: The zone will be divided into a number of layers

with relative thickness as given in the input. Example: If theinput is 1, 2, 2, the zone is divided into three layers where the

two last layers are twice as thick as the first one.




The illustration above shows three different ways of specifying the

layering; Follow base, Fractions and Proportional.

Note that the zone division should reflect the horizon type. If, forinstance, a horizon is of type Base, the zone above should be of type

Follow base, Proportional, or Fractions.

Proportional and Fractions give the least “pinched out” layers and

are usually best for simulation grids.




Model a faultDigitizing

Employ the Make/edit polygons

process to digitize a line that

defines the fault plane.

The new polygon appears at the

bottom of the Input pane.

A simulation fault can be inserted into the simple grid at the position of

existing grid nodes. To approximately give the geometry of the newfault, you can draw a polygon within the simple grid.

The Make/edit polygons process is placed under Utilities on the

Processes pane. When the process is active, tools for digitizing

polygons appear in the function bar at the right of the display window.

Use the process to digitize a line that defines the geometry of the fault.

The new polygon is stored at the bottom of the Input pane.




Model a fault

Convert to fault

The polygon can be converted into a

fault in the active grid

To insert the fault into the grid, make sure that the grid is selected in

the Models pane. Then right-click the polygon you just made, and

select Convert to fault. The polygon is then converted into a fault in

the active grid. The new fault is stored on the Faults sub-folder of the

3D grid.




Model a faultDefine transmissibility

Use the Fault analysis process to

assign transmissibility to the fault

You need to assign a transmissibility multiplier to the fault in order to

use it in a simulation. The transmissibility multiplier defines to which

degree the fault is a barrier to flow. A multiplier of zero means that no

flow goes through the fault.

To assign a transmissibility multiplier to a fault, make sure that the fault

is active, then open the Fault analysis process. In the dialog that

opens, select to assign a constant multiplier, or to define a multiplier

based on standard equations. A new property is created and stored

under the Fault properties folder in the Models pane. Details of how

to define the transmissibility multiplier will be provided later in the

course.




Exercises - Making a simple grid a withsimulation fault

In this exercise, you will make a simple simulation model of a two-

phase black oil case. You will start by defining a simple grid with avertical fault. You will then go through all of the steps required until you

have a model ready for running a simulation. And finally, you will run

the simulation and view the results.

Exercise Workflow• Make a simple grid

• Insert a simulation fault

Exercise Data

In this exercise, we use the Start_2010.pet.

Making a simple grid

Exercise steps1. Open the Start_2010.pet project.

2. Open the Make simple grid process located under Utilitiesin the Processes pane.

3. Select a name for the new grid, for example Simple.

4. On the Input data tab, select the Insert surface option.

5. Drop in the surfaces Top reservoir, Mid, and Base from the

Surfaces folder on the Input pane by clicking the Appenditem in the table button .




6. Drop in the Project boundary from the Input pane into the

Boundary field by clicking the blue arrow.

7. Select the Geometry tab, and click the Get limits fromselected button. As the project boundary is selected on the

Input pane, Petrel will use that as a boundary for the grid.

8. Select a Grid increment of 350 m in both the X and Y

direction. Click OK.






5. Digitize a line that will be used to define the fault plane by first

selecting the Make/edit polygons process in the Utilities

folder in the Processes pane. Then:a. Activate the Make/edit polygons tool in the function

bar. Select the Add new points tool .

b. Digitize a line that follows Fault5 by pointing in the

display and left-clicking. Add a point in the grid cell closest

to the project boundary to make sure the fault is extended

all the way to the boundary.

6. The polygon is stored at the bottom of the Input pane. Rename

it to “Fault polygon” by opening the Settings for it and

changing the name in the Info tab.




7. Make sure the Simple grid is selected on the Models pane.

8. Right-click on the polygon you just made, and select Createsimulation (grid) fault from the drop-down menu. The new

fault is stored in the Faults folder under the simple grid on the

Models pane.

Exercise steps1. Open a 3D window and select to view your new fault.

2. Open the Fault analysis process that is located in the

Property modeling folder.

3. Enter a constant transmissibility multiplier of 0 (sealing fault)

Click OK.

4. Save the project.




Summary

The basics of the Petrel user interface were presented in this

module. In particular, how to open and use windows and how to

access and alter the settings of objects. Also introduced were theeight different panes in Petrel which store and provide access to

data, processes, windows, workflows and simulation results.

In addition, how to make a simple simulation grid with layering

based on surface information was presented along with how to add

a fault to such a grid and how to assign properties to the fault.



Reservoir Engineering Functions • 65

Module 3 - Functions

Introduction

In this module, how to make fluid models (PVT), saturation functions

(relative permeability and capillary pressure), and rock compaction

functions in Petrel, will be covered.

Prerequisites

No prerequisites are required for this module.

Learning Objectives

In this module you will learn:

• How to create a correlation based black oil fluid model

• How to define the initial contact depths and pressure

• How to create correlation based saturation functions

• How to create rock compaction functions based on correlations

• How to import fluid models and rock physics functions from

keyword files• How to edit and visualize the functions in Petrel



66 • Functions Reservoir Engineering

Lesson 1 - Make fluid model

Make fluid model

The Make fluid model process allows you to create black oil models

from correlations and to create compositional and thermal models. In

this course, we will only use black oil models, but we will briefly

explained how to create compositional models.

Correlation library

The correlation library we use incorporates many published

correlations, some of which use the separator conditions as input. All of

the correlations have been tested against an extensive database of

actual PVT (pressure-volume-temperature) experiments at theSchlumberger Reservoir Fluids Center in Edmonton, Canada. Petrel

selects which correlation to use based on the input data you provide

– the API gravity, the reservoir pressure, etc.

The library contains about 70 black-oil correlations - including the ones

most commonly used in the industry.




Black Oil and Compositional Models

ECLIPSE Blackoil and FrontSim

• Black oil simulators

• One component of gas and one

of oil in both vapor and liquid

phase

ECLIPSE Compositional

• Compositional simulator

• Both the vapor and the liquid

phase consists of several

components

Rv

Rs

There will always be two, or frequently three, phases present in the

reservoir during its producing life (oil, gas, water). The proportions, the

composition and the physical properties of the phases may change as

production proceeds, and pressures change. All of the phases areconsidered compressible, although to different degrees.

In a black oil model, the temperature is assumed to be constant.

Typical temperatures at reservoir conditions are 350K~77C~171F. Also,

since both the liquid hydrocarbon phase and the vapor phase are

assumed to consist of mainly one component, it is customary to name

them the oil and gas phase, respectively. The compositional behavior is

modeled by allowing some of the gas component to be dissolved in oil

and some of the oil component to be vaporized in gas.

A compositional fluid model represents the hydrocarbon fluid by aset of components (typically 6-12 for reservoir simulation). An equation

of state is then used to determine the physical properties of mixtures of

these components as a function of pressure and temperature and the

properties of the individual components.




Appropriate Black Oil Models

Fits the Black Oil model.

Unsuited for black oil simulation(use Compositional simulation).

Approximated by Black Oilvarying gas/oil and oil/gas ratiosto mimic small compositionalchanges.

A: Dead Oil

D: Dry Gas

F: Wet Gas,Retrograde

E: Wet Gas

G: Near Critical

Fluid

B: Live Oil,

Initially

Undersaturated

C: Live Oil,

Saturated

Temperature

Pressure

Phase diagrams

The hydrocarbon behavior in a reservoir is often described in terms of a

phase diagram as showed in the illustration above. The phase diagram

relates the fluid state to pressure and temperature in the reservoir. The

upper line of the phase envelope represents the lowest pressure and

temperature limit for the existence of a liquid phase. This line is called

the bubble point line. The lower line represents the upper limit for

pressure and temperature for the existence of a vapor phase. This line

is called the dew point line. The area between the two lines is pressure

and temperature conditions where both a liquid and a vapor phase is

present simultaneously. The point where the bubble point line and the

dew point line meet, is called the critical point. At this pressure andtemperature condition, the vapor and the liquid properties are equal.

Pressure-temperature conditions close to the critical point cannot be

modelled using a black-oil model.




Make a Fluid Model

2. Specify Model type.

1. Select Create new

to define a new fluid

model.1

2

Note : All fluid models

will be stored in theInput pane.

In the process dialog, you need to specify whether to make a black oil,

compositional or thermal fluid model.




Compositional Model1. Select equation of state

from the General tab.

2. Append a row for each

component.1

2

Note: There is no

support for tuning an

equation of state tomatch laboratory

measurements.

You can select pre-defined

components from the drop-down

menu.

3. Go to the Interactions tab

to give interactions and to the

Samples tab to give samples.

3

When you make a compositional model, you must first select an

equation of state at the General tab. Note that there is no support fortuning the equation of state to laboratory measurements. For that, you

will have to use PVTi and import the resulting matched equation of

state.

When you add a new component on the Components tab, you need to

type in the molecular weight and then click the Fill table button to fill

in the rest of the table according to the equation of state. Note that if

you later change the equation of state, you must return to the

Components tab and click the Fill table button again.




Make a default Compositional Model

1. Select model type –

Compositional.

2. Use the drop-down

menu to specify

default model.

1 2

All sub-tabs are filled

with preset values.

Make a default Black Oil Model

2

1

1. Select Black oil as Model type.

2. On the General tab, specify whichphases are required (enter required

properties in the following tabs).

3. Or use one of the defaults.

4. Specify an initial condition.

3

4




There are four default black oil models to select from:

Dead oil. Two phases, oil and water. Bubble point pressure lower

than minimum reservoir pressure, hence no gas will boil out of

the oil.Heavy oil+gas. Three fluid phases, oil, gas, and water. The oil has

API gravity of 26.

Light oil+gas. Three phases, oil, gas, and water. A lighter oil with

API gravity of 45.

Dry gas. Two fluid phases, gas and water.

To make a default model, select one of the models from the drop-down

list and go to the Initial conditions tab to specify the initial fluid

contacts.

Make a model using the settings

General tab

• Select phases.

• Enter pressure and temperature

in the reservoir.

In addition to the four default fluid models, you can make black oil

models by filling in the settings in the process dialog. Based on the

settings, Petrel will select a model based on correlations.

The General tab

In the General tab, you specify which fluid phases that are present and

also the reservoir pressure and temperature.

Reservoir conditions. This is where the minimum and the maximumpressure in the reservoir is specified. In addition, you must enter the

temperature in the reservoir.

Separator conditions. Here you can specify the pressure and the

temperature at separator conditions. Some of the correlations need

information on separator conditions.




The Gas tab

GasInformation on the gas phase

composition entered here is

used to select correlations.

Correlations

Leave as Default to allow Petrel

to select correlations based on

your input.

Gas properties. Enter the density or the gravity of the gas phase. If

you are defining a dry gas, you must type in the vaporized gas/oil ratio.

You can also select which correlations to use or you can make Petrel

select, based on the input you give.

If you have information on the concentration of each component of the

gas phase, this can be entered here. Note that this option is only used

to select which correlations to use, it does not mean that you aredefining a compositional model.




The Oil tab

Specify gravity and bubblepoint pressure.

Correlations -

are reported on the Statistics

tab of the fluid model

Oil properties. Here, you need to specify the oil density or the oil

gravity (API gravity: The usual range starts with water density at 10

degrees and rises to volatile oils and straw colored condensate liquids

around 60-70 degrees). In addition, you must enter the Bubble pointpressure or the Solution gas/oil ratio at the oil/gas contact. Note

that if the bubble point pressure you supply is lower than the minimum

reservoir pressure, then no gas will boil out of the oil. Consequently,

you get dead oil. Also, notice that unless you plan to give a depth

dependent Solution gas/oil ratio, the bubble point pressure must be

equal to the pressure at the gas/oil contact as specified in the Initialconditions tab.

You can either select correlations, or leave it to Petrel to select based

on the input you give. Notice that the correlations that are used to makethe fluid model are listed on the Statistics tab of the settings dialog

for the fluid model.




Initial conditions tab

1. From contact set.

2. Define in the table.

3. Add columns to thetable to add initial

condition regions.

1

2

3

Initial conditions tab

In the Initial conditions tab, you can give the initial fluid contacts as

well as the pressure and the capillary pressure at those contacts. This

information is used in the simulator to calculate the initial pressure and

phase saturations in every grid block.

For each fluid region, you must specify a reference depth (datum) and a

corresponding pressure, gas-oil contact depth, and water contact depth

(depending on which phases you have). In the Define simulation caseprocess you will have the opportunity to associate each of these initial

condition regions with a region of the grid.

There are two ways you can define your initial conditions:

Contact set: If you have an existing contact set, you can select the

Use contact set option and drop in the contact set from the

Petrel explorer. The option Target number of initialconditions will control how many regions to make from a

contact set (for example, if a tilted surface is made in the




Make contacts process). This algorithm is iterative and

cannot guarantee to get exactly the number of targets

specified. For example, if you enter 10, but there are only two

distinct values in the surface, you will only get two regions.

Table: If you not using contact set, you can enter the details of

each initial condition in a table. The table consists of a column

for each initial condition region; columns can be added or

removed using the usual Petrel table manipulation buttons.

By default, the gas-oil contact is set as Datum. Also, the pressure at

Datum is defaulted using a pressure gradient of 0.0981 bar/m over the

depth given by (surface elevation - datum depth). To enter a specific

pressure or datum depth, select the check box.

Note that unless you plan to give a depth table for solution gas/oil ratio

and bubble point pressure, the pressure at the gas-oil contact must be

equal to the bubble point pressure input, specified on the General tab.

Make contacts

Make contacts is the process

where the contacts to be used in

the Volume calculation and

Simulation processes are made

To keep the fluids

in a stair step condition, you

will need to define the model

as such (with an active

aquifer, capillary pressure,

etc). If you just put a tilted

surface for the contact, and

then run the simulator, the

fluid will gradually slump

down to a flat contact.




To use contacts as input to the Make fluid model processes, you must

define them in a separate process in Petrel, called Make contacts.

The purpose of this is to be able to enter different types of contacts,

such as constant values, dipping contacts and surfaces, and you can

choose to use different contacts for each zone and each segment or the

same contacts for the entire 3D model.

Another purpose of contacts is to visualize them together with one of

the horizons. This will show the contact contour on the surface together

with colored intervals for each hydrocarbon interval. This is useful when

displaying the aerial extent of the hydrocarbon intervals.

Make contacts

Define fluid contacts

1. Append the number of contacts.

2. Define the contact type and name.

3. Define the contact level.

Can be a different value/surface for

each segment and zone.

1 2

3

Make contacts - Procedure1. Open the Make contact process.

2. Choose to Create new contact set.3. Enter the type of contacts to be created, and change the name

(if other than default).

4. Enter the contact level.




Contact level• Can be a constant value or a surface. To enter a constant

value, type the value directly into the cell. If it is a surface,

select the little check box and use the blue arrow to copy the

surface that represents the contact into the cell.

• To use different contacts for each segment and zone, clear the

options Same for all zones and Same for all segments.

Fluid variations with depth

Right-click an Initial condition and selectSpreadsheet to enter a depth table.

Specify the bubble point or the Rs value at

each depth. If you specify one, then theother is calculated using the correlations.

Vertical variations in PVT must be given in a

spreadsheet.

Composition of oil is frequently a function of depth

• Solution gas/oil ratio (Rs) or Bubble point pressure (Pb

• Vaporized oil/gas ratio (Rv) or dew point (Pd)

(No correlations available to create vaporized oil PVT – input

manually or import)

To model the variation with depth, you have to fill in the Spreadsheet located under the Initial condition sub-folder of the fluid model folder.

You can specify the bubble point or the Rs value at each depth. If you

specify Pb, then Rs will automatically be calculated and vice-versa,

using the correlations the fluid model is based on.




Entering a depth table is optional. If a table is not entered, the

dissolved gas concentration in under-saturated oil is set equal to the

saturated Rs value at the gas-oil contact everywhere. This is the Rs

value that you specified on the General tab when you made the fluid

model.

If the bubble point pressure (specified on the General tab of the Makefluid model process) is not equal to the pressure at the gas-oil contact

(as specified on the Initial conditions tab), a depth table is required.

At any position in the reservoir, the Rs value derived from an Rs or Pb

versus depth table, is subject to an upper limit equal to the saturated

value at the local pressure, since the Rs value cannot exceed this.

Spreadsheets

You can view/edit a fluid model

in spreadsheet format.

You can copy and paste to/from

existing tables.

By right-clicking the oil or gas phase of the fluid model, you can access

the data in a spreadsheet format. Data can be copied/pasted from/to

those spreadsheets from Excel.




Fluids data can beplotted in a

function window.

Plotting

Import

Black oil models exported

from PVTi can be imported.

The status of the import is

reported in the message log.




You can import fluid models generated in PVTi, or you can import Eclipse

keyword files.

Exercises – Make fluid modelThere are several ways to create a fluid model in Petrel. You can use

the Make fluid model process to generate a fluid model from

correlations, you can import data or you can define a fluid model by

using spreadsheets.

Exercise Workflow• Make a black oil fluid model

• Reviewing fluid model settings

• Import a keyword fluid model

• Plot the fluid model

Exercise Data

In this exercise, we will continue to use the project from the previous

exercise.

Make a black oil model from correlations

In this exercise, we will create a black oil fluid model based on

correlations using the Make fluid model process in Petrel. The outputfrom the process is a fluid model that can be used by the simulator.

Exercise steps1. From the Processes pane, open the Simulation folder and

open the Make fluid model process.

2. Select Create new fluid model.3. Click on the Use presets button and select Light oil + gas

from the drop-down menu. Observe that the process window is

filled with default values.

4. On the General tab, change the Maximum pressure to 460bar.




5. Inspect the Gas tab, accept the default settings.

6. Select the Oil tab. Change the Bubble point pressure to 200

bar.

7. Go to the Initial conditions tab. To specify the initial

reservoir conditions for the model, you can either drop in a

contact set or you can enter a table of contact depths and

pressures. In this exercise, we will use the table and enter a

value for the gas-oil contact to -1600m and the water contact

to -2600 m.

8. Enter a pressure at datum (the gas-oil contact) of 200 bar.

9. Click OK in the Make fluid model process dialog.

If the datum depth

lies above the gas-oil

contact, the pressure refers

to the gas phase.

If the datum depth lies belowthe water-oil contact, the

pressure refers to the water

phase. Otherwise, the

pressure refers to the oil

phase.




Reviewing fluid model settings

In this exercise, we will inspect the settings for the fluid model we just

created to see how we can edit and change the model.

Exercise steps1. In the Input pane you can now see that a Fluids folder has

been added. This is where the fluid models are stored.

2. Expand your fluid model inside the Fluids folder and then

right-click on Oil and select Spreadsheet from the context

menu. This opens a spreadsheet view of the oil properties that

vary with pressure.

Import a keyword fluid model

In this exercise, we will import a fluid model from a keyword file. Thisfile can be an included file to the simulation deck, or the main .DATA file

of the simulation deck.

Exercise steps1. Right-click on the Fluids folder and select Import (on

selection). Navigate to the ImportData > Functions >FLUID.INC file, and click Open to do the import.

2. On import, you may get a message that some keywords were

not imported. You can find those keywords in the Message

log. These keywords do not contain PVT data.3. After importing, a new fluid model is added to the Fluids

folder in the Input pane. Check the imported data by using the

Settings panel and the spreadsheets.

4. The fluid you imported does not have an initial condition,

hence, an initial condition must be added before the fluid can

be used in a simulation model.

Plotting the fluid model

In this exercise, we will plot the fluid model in a function window.

Exercise steps1. Insert a New function window from the Window menu,

and select the check box next to Oil formation volumefactor in the Oil folder of the imported Black oil model 1.

2. Use the Select/pick mode tool and click anywhere on




any of the curves. The property name and value appear in the

status bar. If you cannot see the status bar, enable it with the

View > Status bar command.

3. Deselect to view the Oil formation volume factor and select

the check box next to Oil viscosity instead.

4. Any changes made in any of the settings panels and

spreadsheets will be reflected in what you see in the function

window.




Create multiple viewports – Optional

In this exercise, we will set up a new plot window with four function

viewports so we can make a report of the fluid model and inspect more

data in one view.Exercise steps

1. Insert a New plot window from the Window menu.

2. There are two ways to create multiple viewports in the plot

window:

a. Go to the Windows pane and find the inserted plot

window. Open the settings for Plot window 1 [Any] and

go to the Setup multiple viewports tab.

Or,

b. From the toolbar, click on the New object in windowbutton on the toolbar and select Create/align multipleviewports.




3. In the settings for ‘Plot window 1 [Any]’ dialog, select

Function viewport(s) from the New viewport type drop-

down menu. Define Number of rows: 2 and Number of

columns: 2. Then click the

Setup viewportsbutton

and close the settings window by

clicking OK.

4. You should now have four function viewports ready to use for

plotting the line data. The active viewport is shown with a red

border. Click inside a function viewport to make it active.

5. As an example, select the following data to plot from the Lightoil + gas fluid model:

a. Top left viewport: Oil formation volume factor.

b. Top right viewport: Oil viscosity.

c. Bottom left viewport: Pressure and the fluid contacts fromInitial condition 1.

d. Bottom right viewport: Gas formation volume factor.

6. You should have a plot window similar to the one shown

below:







Lesson 2 Make rock physics functions

Make rock physics functions

Capillary pressure curves Rock compactionRelative permeability

The Make rock physics functions process is used to create functionsthat represent the physics of the rock and the interaction between rock

and fluids, or saturation functions and rock compaction functions.




Rock compaction function

Used to make rock compaction tables

from a choice of correlations to modelcompaction drive.

Rock compaction functions are tables showing pore volume multipliers

versus pressure, or a single rock compressibility value used by thesimulator to calculate the pore volume change. The compaction can be

thought of as the reduction in the pore volume as a function of

pressure. Creating rock compaction functions using the Make rockphysics functions process will also create a transmissibility multiplier

versus pressure curves. These are set to 1.0, by default.




Rock compaction function

Use presetsThere are three preset compaction

functions to select from.

Or specify

1. Correlation

2. Rock type

3. Number of table entries

Then give:

1. Porosity, constant or property

2. Pressures

By clicking the Use presets button, you will be given three compaction

functions to select from. Alternatively, you can manually fill in the fields.

If you select the correlation User defined, you need to supply acompressibility and a reference pressure (equivalent to using the ROCK

keyword). Otherwise, the compressibility is computed using the

correlation you select from the drop-down menu (the ROCKTAB keyword

is used). In both cases, the result of the process is a curve showing pore

volume multipliers as a function of reservoir pressure. The multiplier is

always one for the reference pressure, meaning that at this pressure

the pore volume is equal to the initial pore volume.

Note that when adding a rock compaction function to your simulation

case, the simulator will no longer compute the (initial) pore volumetaking only the porosity property that you supply on the Grid tab of the

Define simulation case process as input. Now the simulator is also

using the rock compaction curve. That is, for each grid block a pore

volume is assigned by multiplying, the original grid pore volume with

the pore volume multiplier. Consequently, if the pressure for a grid block

is equal to the reference pressure, the volume is unaltered. If the




pressure is lower, the volume is reduced. However, if you want to model

a reservoir that is already compacted at the beginning of the simulation,

you need to define a reference pressure that is accordingly higher than

the initial cell pressures.

If you want to use the pore volumes as given by the porosity property to

initialize your model, you have to use the Keyword Editor and change

the second entry of the ROCKOPTS keyword to STORE.

Saturation function

Make relative permeability curves based

on Corey correlations

Used to calculate initial

saturation in each cell

Used to calculate the

phase mobility

When two or more immiscible fluids (for example, oil and water) are

present in the formation, their flows interfere. Therefore, the effective

permeability to oil flow (ko) or water flow (kw) is reduced. Furthermore,the summation of effective permeability is always less than or equal to

the absolute permeability (k). The effective permeability depends not

only on the rock itself but also on the relative amounts and properties

of the different fluids in the pores. In a given rock, ko and kw will vary

as oil and water saturations, So and Sw, vary.




Relative permeability is the ratio of the effective permeability to the

absolute (single homogeneous fluid) permeability, thus, for an oil-water

system the relative permeability to water, krw, is equal to kw/k.

Similarly, the relative permeability for oil, kro, is equal to ko/k. Relative

permeability is usually expressed in percent or fractions and never

exceed the unity (1 or 100%).

In Petrel, you can use the Make rock physics process to make

relative permeability curves as functions of saturation based on Corey

correlations.

Saturation function

1. Preset values are available for

sand, shaly sand and fracture

(for dual permeability models).

2. The number of table entries

controls the size of the tables

passed to the simulator.

The input to the Corey correlations depends on the fluid phases you

select to include in the model.

For gas:

- Sgcr: the critical gas saturation. - Corey Gas: Corey gas exponent for values between the minimum

water saturation and (1 – Sorg).

- Krg@Swmin: Relative permeability value of gas at the minimum

water saturation.

- Krg@Sorg: Relative permeability value of gas at the residual oil

saturation.




For oil:

- Sorw: Residual oil saturation to water. Note that (1 – Sorw) >

Swcr

- Sorg: Residual oil saturation to gas. Note that (1 – Sorg) > Swcr - Corey O/W: Corey oil exponent for values between the minimum

water saturation and (1 – Sorw).

- Corey O/G: Corey oil exponent for values between minimum

water saturation and (1 – Sorg).

- Kro@Somax: Relative permeability of oil at the maximum value

of oil saturation.

For water:

- Swmin: Minimum water saturation.

- Swcr: Critical water saturation. This must be greater than or

equal the minimum water saturation.

- Corey Water: Corey water exponent for values between Swcr and

(1 – Sorw).

- Krw@Sorw: Relative permeability of water at the residual oil

saturation value.

- Krw@S=1: Relative permeability of water at a saturation value of

unity.

Oil-water capillary pressure:

Notice that in the lower part of the process dialog you can enter input

to generate a curve for oil-water capillary pressure. You need toprovide:

- maximum capillary pressure

- water saturation when the capillary pressure is zero.




The figure shows relative permeability curves for a water-wet formation

containing only oil and water. The values of krw and kro vary with the

saturation. The curves illustrate that at high oil saturation, kro is large

and krw is small; the oil flows easily and little water flows. At high

water saturations, kro is small and krw is large; now the water flows

easily and little oil flows.

Irreducible saturations

When the Kro value reaches zero, the oil remaining in the pore space is

immovable; the corresponding value of oil saturation at which this

occurs is the residual oil saturation (Sorw).

The Krw curve becomes zero at an Sw value indicated on the figures asSwcr. At this saturation, only oil flows in the formation and the residual

water is immobile. In a water-wet formation, there is always a certain

amount of water held in the pores by capillary forces. This water cannot

be displaced by oil at pressures encountered in formations, so the

water saturation does not reach zero.




Spreadsheets

You can view/edit rockphysics functions in a

spreadsheet.

Right-click on the Rock

physics functionsfolder and select

Spreadsheet…

Spreadsheets for rock physics functions

The spreadsheet for rock physics functions has some basic validation

triggers. In the case of saturation functions, the saturation values must

increase down the column, and the relative permeabilities must be leveland increase or decrease down the columns. In the case of rock

compaction functions, the pressure must increase down the column,

and the pore volume and transmissibility multipliers must be level and

increase or decrease down the columns.

The simulator will also run a validation on the data ranges in the tables,

and will issue a warning if the end point in the tables exceeds 100%

(1.0)

Capillary pressure

In a thick reservoir that contains both water and hydrocarbon columns,the saturation may vary from 100% water at the bottom of the zone, to

a maximum oil saturation (and irreducible water saturation) at the top.

There is a gradual transition between these two extremes in saturation.

The transition interval may be very short for porous and permeable

formations, or it may be quite long in formations of low permeability.




Capillary pressure is a function of the elevation above the free water

level (FWL) and the difference between densities of the wetting (water)

and non wetting (oil) phases.

Capillary pressure dataOil-water

You can make oil-water capillary

pressure curves using correlations.

Capillary pressure dataGas-oil

Petrel does not have a correlation

for gas-oil capillary pressure data.

The data can be entered in the

spreadsheet.




Plotting

Import rock physics functions

Functions can be imported to theRock physics function folder.

The status of the import is reported

in the message log.




Rock physics functions can also be inserted manually into Petrel by

right-clicking on the Rock physics functions folder in the Input pane

and selecting the option Insert rock compaction function or Insertsaturation function. An empty function will appear in the folder. In

turn, this can be right-clicked and you can select the option to open a

spreadsheet for editing the function. The function tables can then be

entered manually, or copied from an external application.

Exercises – Make rock physics functions

There are several ways of creating rock physics functions in Petrel. You

can use the Make rock physics functions process to generate

functions from correlations, you can import data, or you can define the

functions using spreadsheets.Exercise Workflow

• Make a saturation function

• Make a rock compaction function

• Reviewing rock physics functions data

• Import a keyword rock physics function

• Plotting the rock physics functions

Exercise Data

In this exercise, continue to use the project you used in the previous

exercise.

Make a saturation function

In this exercise, we will create saturation functions based on Corey

correlations using the Make rock physics functions process. The

output from the process will be tables that can be exported for use by

the simulator.

Exercise steps1. From the Processes pane, expand the Simulation folder and

open the Make rock physics functions process.

2. Select Saturation function from the Function type drop-

down menu.

3. Select Create new function, then select Sand from the Usepresets drop-down menu.

4. Click Apply in the Make rock physics functions process

dialog.

You can insert

sub-folders to the Rock

physics functions folder to

organize the fluid models.This way you can use Petrel

as a repository for the rock

physics functions you

regularly use.




5. Expand the new Rock physics functions folder on the Input pane. This is where your saturation function is stored.

6. Open a Function window, and select to display the saturation

function.

Exercise steps

The shape of the relative permeability curve and the number of points

in the table is set in the process dialog.

1. Open the Make rock physics functions process again.

2. Select Edit existing function, and then make sure the Sand

function is selected from the drop-down list.

3. Change the number of Table entries to 8.

4. Change the Corey O/W to 1 and the Corey water to 2.

5. Change Sorw to 0.15.

6. Click OK.

7. Display the new function in the Function window.




Make a rock compaction function

In this exercise, we will create rock compaction functions based on

correlations using the Make rock physics functions process. The

output from this process will be rock compressibility tables that can be

used by the simulator.

Exercise steps1. Open the Make rock physics functions dialog.

2. Select to create a new function.

3. Select Rock Compaction Function from the Function type

drop-down menu.




4. All the necessary fields on the dialog can be filled in with

default values by selecting an option from the Use presets

list. Click on Use presets and select Consolidatedsandstone from the drop-down menu.

5. Click OK in the Make rock physics functions process

dialog.

6. The rock compaction function is stored in the Rock physicsfunctions folder in the Input pane.

You can also make a rock compaction function based on constantcompressibility.

Exercise steps1. Open the Make rock physics functions dialog.

2. Select Rock Compaction Function from the Function type

drop-down menu.




3. Select Create new function and give the new function the

name Constant.4. Select to use 8 table entries.

5. From the Correlation drop-down menu, select User defined.

6. Enter a Compressibility of 0.00001.7. Click OK.

8. Display both compaction functions in a function window.

Reviewing rock physics functions data

In this exercise, we will inspect the settings for the rock physics

functions we just created to see how we can edit and change the

functions. We will also plot the functions in a function window and do

some graphical editing directly on the curves.

Exercise steps1. Right-click on the Rock physics functions folder and select

Spreadsheet from the drop-down menu. This will give you a

spreadsheet view of the rock functions.

2. You can select which function to view by using the drop-down

menu at the top of the panel. Similarly, you can change

between the relative permeability tables and the capillary

pressure table by using the drop-down menus.

3. Click Cancel to close the spreadsheet.




4. Insert a function window from the Window menu and click in

the check box in front of one of the saturation functions to plot

the curve for that function.

5. There are two ways to edit the functions. You can either makeedits in the spreadsheet, or directly on the curves in the

function window using graphical tools. There is no undo, so make a copy of a function before you start editing.

6. Click on the Select/pick mode tool in the function bar

and click on a point on one of the curves. Information on this

point is displayed in the status bar.

7. Click on the Select and edit/add points tool in the

function bar. Click on one of the points and drag this to another

position to update the function. Note that there is no undo for

this operation!

8. Move the mouse pointer a little bit beyond a point on the curve

and click on the line itself. Hold the left mouse button and

drag. A new point is added to the function. You can move the

point, and the function table are updated accordingly.

9. Finally, click on the Selected and edit line tool . Click on

one of the points and you will now be allowed to move this upor down, but not horizontally.




Import a keyword rock physics function

In this exercise, we will import rock physics functions from keyword

files. The file can be an include file to the simulation deck, or the

keywords can be in the main .DATA file of the simulation deck. Notethat the path to include files must be reachable.

Exercise steps1. We will import both types of rock physics functions in one

operation. Right-click on the Rock physics functions folder

in the Input pane and select Import (on selection).2. Navigate to and select ImportData > Functions >

ROCKPHYSICS.INC and click Open to start the import. If

there are any keywords that are not imported, they will belisted in the Petrel message log.

3. View the imported data by using both the spreadsheets and the

function window.




Summary

How to create a fluid model and rock physics functions using the Makefluid model and Make rock physics functions in Petrel was covered

in this module. How to edit the functions in a spreadsheet and to plotthe functions in function window was also covered. Finally, you have

learned how to import functions from keyword files and how the

functions are stored and organized in Petrel.





Reservoir Engineering Initializing the model • 107

Module 4 - Initialize theModel and View 3DProperties

Introduction

In this module, you will learn how to use the Define simulation caseprocess to initialize the model. We will also explore the 3D viewing

options in Petrel.

Prerequisites

No prerequisites are required for this module.

Learning Objectives

In this module you will learn:

• How to initialize the model

• To use 3D visualization windows

• How to define and use filters



108 • Initializing the model Reservoir Engineering

Lesson 1 – Initialization of the model

Introduction

The Define simulation case process allows the engineer to pull

together the 3D grid with the fluid and rock physics functions toinitialize the model, that is, to compute initial saturations, pressure and

transmissibilities. The process is also used to select which simulator to

run, and which development strategy to use.




Define simulation caseGrid properties

Porosity and Permeability

is set on the Grid tab of the

Define simulation case

process.

Porosity and Permeability is

automatically inserted on the

Grid tab when you select a

3D grid.

Additional Grid Properties

For example, insert a water

saturation to apply end point

scaling.

• Add a row by clicking

• Select template

• Drop in the 3D property




In addition to permeability and porosity (required input), you can drop in

other properties that are defined in the 3D grid. For example, you can

select to use a local grid set, fault transmissibility multiplier, or

endpoint scaling for saturation functions.

Three ways of Initializing

Enumeration (Black oil)

The user inserts initial

saturation and pressure as

3D grid properties on the

Grid tab.

Equilibration

The simulator computes

initial saturation and

pressure using the Fluid

model and the Saturationfunction that is inserted on

the Functions tab.

Restart

Initial saturation and

pressure is read from arestart file.

Initial gas, oil, and water pressure distribution and initial saturation

distributions must be defined in the reservoir model. Pressure data is

usually given with reference to a datum depth. In Petrel, the datum

depth is mean sea level by default.

There are three initialization options:

Equilibration – Initial phase pressures and saturation are

computed by the simulator, using the fluid model. The

equilibration facility is a means of calculating the initial

conditions on the basis of hydrostatic equilibrium. If necessary,

the reservoir can be divided into separate “equilibration

regions” in which hydrostatic equilibrium exists independently

of the other regions. The number of equilibration regions is

specified in the Make fluid model process. Within each




equilibration region, all grid blocks must use the same pressure

table for their PVT properties, but they can use different rock

physics functions tables as specified in the Make rockphysics functions process.

Enumeration – The initial value of pressure, saturation, and

bubble point pressure is set explicitly in each grid block by the

user. The 3D grid property must be dropped into the Grid tab of

the Define simulation case process.

Restart – The initial conditions are read from a restart file of a

previous run.

FunctionsBlack oil (PVT)

Left-click the Black oil

fluid model (PVT).

Drop in the initialcondition of the fluid

model.

Deselect Initialize by

equilibration if you use

enumeration.




FunctionsBlack oil regions

Different fluid models can be

assigned to different regions.

Any discrete property (such as

segments) can be used as a region

index property.

Fluid model: Spatial variations

Initially, the fluid model in reservoirs may vary vertically and aerially.

This can be modeled by assigning separate fluid models to separateregions of the model. It is important to understand how the fluid model

is used in a simulator with fluid movement. When fluid moves from one

region to another, the simulator will change the fluid model used, such

as the viscosity and formation volume factor, as the fluids cross into the

separate regions. Unless mixing between different oils has occurred or

the pressure has changed, the fluid properties will remain the same as

they move through the 3D grid.




FunctionsRock physics

Drop in:

• Relative permeability curves

• Rock compaction function

Select Region index property

to assign different functions to

different rock types.

Initialize by equilibration

Given the fluid densities, the equilibration procedure sets up saturationagainst depth curves so that in the transition zone, when two phases

are mobile, the hydrostatic pressure variation is balanced by the

capillary pressure between the phases.

Separate rock

physics functions should be

used for each significant rock

type.




EquilibrationCompute phase pressures

The contacts in the Fluid model

are used.

Phase pressure is computed

using the fluid density as input.

Within each equilibration region, the calculation is performed in two

stages. In the first stage, an internal table of phase pressures and Rsand Rv against depth is set up. In the second stage, the fluid conditions

in each grid block in the region is computed using interpolated values

from the table.




EquilibrationSaturation in the water, oil, and gas zone

Oil zone: So = 1-SwminGas zone: Sg = 1-Swmin

In the second stage of the equilibration calculation, the local fluid

conditions are determined in each grid block in the equilibration region.

The internal table is interpolated to obtain the values of Po, Pw, Pg, Rsand Rv at the grid block center depth. The water saturation is

determined by inverse look-up of the water capillary pressure table.




EquilibrationSaturation in the transition zones

• Calculate Pcog and Pcow

in the transition zone.

• Find Sg and Sw byinverse lookup from the

capillary pressure curves.

Strategies

The Strategies tab can be left

blank when initializing the model.

Development strategies and

Well segmentation will be described

later in the course.

You can use a global

permeability log to compute

the KH term of the

connection transmissibilityfactor. For every well, Petrel

will check if it has a

permeability log that will be

used for computing KH.

Otherwise, the grid

properties will be used as

usual.’




Results3D initial properties

Request to write out initial

saturation and pressure.

Non standard 3D properties can

be added using Additional

Properties (e.g., bubble point

for each cell).

AdvancedSelect grid type

The Editor gives access to all

simulator keywords including

those not supported from Petrel.

Select:

• Grid export type (OPF default)

• Simulator version• Which queue to send the job to




A choice of formats for exporting grid data from the Models pane has

always been available in Petrel. However, you can also select these

formats from the Advanced tab in the Define simulation case

process.

The considerations in choosing which format to use are:

Pillar geometry: Petrel supports vertical, straight, listric and

curved pillar geometry. Several of the export formats only

support vertical and straight pillars. If your grid contains curved

or listric pillars and you use a format that does not support it,

the grid will be distorted on export. Check this in the

Statistics tab of the grid settings.

ASCII or Binary: This is important if you are planning to edit the

data outside Petrel. In that case, you need to export the data in

ASCII format.

Properties: Some of the formats do not include the properties on

export. In that case, you need to export them separately.

Compatibility: Not all formats are supported by all simulators or

third party applications. Check the available formats in the

other application before exporting.

File size: Some of the formats provide a higher efficiency

compared to others, resulting in much smaller files. This will

minimize both disc space requirements and the time needed to

move files between systems (if you are running remotely).By default, the OPF (Open Petrel Format) format is used for all

simulation runs. It supports curved and listric pillars, is binary and

includes the properties. Note that ECLIPSE has to be 2005a version or

later in order to read this format.




AdvancedTransmissibilities tab

Transmissibility and pore volume

multipliers are written to the

simulator deck.

Use the Transmissibilities tab to:

• Set a minimum pore volume

• Compute transmissibility in Petrel

and export to the simulator

Typically, the individual simulators have calculated the pore volume of

cells, fluid transmissibility and thermal conductivity between them.

These are straightforward calculations, dependent upon the grid

geometry and properties and need only be calculated once prior to thefirst simulation step. The advantage of sending these to the simulator is

that the set of connections and their strengths will be the same

whichever simulator is being used. The transmissibility and pore volume

values are sent from Petrel to the simulator as keywords or inside the

GSG file when the option Calculate and export transm. and porevolumes is selected. FrontSim does not support this feature.




Exercises – Initialization of the model

The next exercises show you how to initialize the model.

Exercise Workflow• Initialize the model

Exercise Data

In the following exercises, we will continue with the project we have

made earlier. Alternatively, you may load the project Mod_3_Completed.pet from Backup Projects folder.

Initialize model

In this exercise, we will initialize the 3D model with fluid and rock

physics functions. We will leave the development strategy field empty.

Exercise steps1. In the Processes pane, expand the Simulation folder and

open the Define simulation case process.

2. Select Create new case and name the new case Simple.

3. Make sure the Simulator is set to ECLIPSE 100, and the Grid

is set to Simple.

4. In the Grid tab, deselect the check boxes in front of

Permeability and Porosity.

5. Enter a permeability of 1000 in the I- and the J- direction andof 50 in the K-direction.

6. Type in a porosity of 0.12.




7. Go to the Functions tab and select the Drainage relativepermeabilities in the left panel by left-clicking it.

8. Drop in the saturation function Saturation function 1 that

you imported in the Input pane (by selecting it) and clickingthe blue arrow in the dialog.

9. Still in the Functions tab, select the Black oil fluid model from the list in the left panel.




10. Ensure that the Initialize by equilibration option is selected.

11. Drop in the Initial condition 1 of the black oil model, Lightoil + gas, that you created earlier. As you only have one

region, there is no reason to use a region index property.

12. Select the Rock compaction function from the list in the left

panel. Drop in the Rock compaction function 1 from the

Rock physics functions folder in the Input pane.

13. The Strategies tab should be left empty as you are only

initializing. If there is an empty row, delete it by selecting the

row and clicking the Delete selected row(s) in table button

14. Click Apply to save the case. The case is saved to the Cases

pane.

15. Click Run. ECLIPSE 100 is launched. Wait for the initializationof the case to finish.

Once the run is finished, go to the Cases pane, right-click on the

simulation case (ECLIPSE 100) and select Show print file. This will

open the print file in your default text editor.

At the bottom of this file, you will find the initial fluid in place report.

You can view the initial properties that are stored in the Simulationgrid results folder on the Results pane. The next lesson explains how

to view 3D data.




Lesson 2 – 3D Viewing

3D Viewing

The simulator loads the results,

and a folder Simulation grid

results is added to the Results

pane

Three sub-folders :

- Composite results

- Static

- Dynamic

Use the Cases pane to selectwhich simulation case to view

3D Viewing

Time step animation

You can use the report steps

available for the property. To

view report steps, select to

step by - Displayed You can use the report steps

from another property. Select

to step by - SelectionYou can specify the report

steps. Select to step by

- User Interval

Set current date and time of

display.




3D results from simulation are accessible from the Results pane.

To display simulation results, you must select a property and a

simulation case. If the property is time dependant, the time player is

used to animate the display through time.

In the folder Composite results, properties are stored as ternary

properties (saturation), vectors, and tensors. The Static folder stores

static input data to the simulators (INIT file). The Dynamic folder

contains data from the restart file and these typically change with time.

3D Viewing

1D filters

Right-click the property and select

Create 1D filter...

A 1D filter can be used to limit the

range of cells displayed for any

property.

Use the property from relevant

case.

Select the relevant report step.

Right-click on a property in the Simulation grid results folder and

select Create 1D filter. In the dialog that opens, you can drag the

sliders to select the range of values you want to filter out. Here, youspecify which simulation case the property is referring to and also

which report step the filter should be applied to. The filter is stored on

the Input pane under the Filters folder, and can be turned on and off.

The time player

speed can be changed from

the Project settings menu.

The simulation grid

results properties can beconverted to grid properties,

and will be stored in the

Properties folder on the

Models pane.

This can be done to access

more property operations, for

example, map creation.




3D Viewing

I, J, K layer filter

You can view all cells with

the same I, J, or K index by

pressing the filter symbol in

the function bar.

The filter tools are available

in the function bar when any

of the property modeling

processes are active.

3D Viewing

Well filter

Right-click on the Well filtersfolder and select Insert new

well filter. Specify top and base of the

filter.




Right-click on the Well filters folder under the Wells folder on the

Input pane to insert a new filter. In the dialog that opens, you can

select which interval of the well trace you want to display. The filter

applies to both well logs and traces.

The new filter takes effect when the check box in front of it is selected.

User filters

You can make filters interactively from function and histogram

windows.

In a histogram window, you can drag a section along the x-axis to

specify the filter. The new filter will appear on the Input pane and can

be applied to other properties. In the illustration above, the histogram

window is used to make a filter for high values of porosity. This filter isapplied in a 3D window to show oil saturation in high porosity cells.

It is also possible to create a filter from a function window. For

example, a cloud of data points can be selected from a cross-plot of

two properties.




3D Viewing

Ternary property display

Select Saturation from the

Simulation grid results

(Composite results sub-folder).

Activate Show/hide auto legend

from the toolbar.

General intersection




Right-click on the Intersections folder on the Models pane and select

Insert general intersection. An intersection plane is added to the

folder.

When the general intersection is displayed in the 3D window, theintersection toolbar appears.

Click the Toggle visualisation on plane tool button to enable

visualization on the intersection plane. Once this tool is activated,

subjects with blue check boxes can be displayed on the intersection.

Use the Manipulate plane tool from the function bar to drag the

plane.

Intersection window

The intersection plane can be

turned into an intersection window.

Right-click the general intersection and select Create intersectionwindow to display your general intersection in an intersection window.

Select the check box in front of the subjects to put them into view. If

you drag the general intersection in the 3D window, the intersection

window is automatically updated.




Exercises – Results viewing

In the previous exercise, you initialized the 3D grid. This exercise will

show you how to display 3D properties.

Exercise Workflow• View 3D simulation data

• Use filters

• Use of general intersection planes

• The multi-value probe

Exercise Data

For this exercise, continue to use the project you used in the previous

exercise.

3D viewing

Your simple grid is now initialized and the initial properties are stored

in the sub-folders of Simulation grid results on the Results pane.

You can view any of the initial properties, such as saturation or

pressure in a 3D window. The exercises demonstrate how to apply

different filters for a better view.

Exercise steps1. Open a new 3D window.

2. Go to the Cases pane and select the relevant case.3. Go to the Results pane, and expand the Simulation grid

results folder. Then, expand the Dynamic sub-folder. Select

to display Water saturation (SWAT).

4. Click the Show/hide grid lines button in the function bar

to display the grid lines. If the icon is not on the function bar,

activate the Define simulation case process on the

Processes pane.

5. Click the Show/hide axis button in the menu bar to

display the coordinate axis.

6. Click the Show/hide auto legend button in the menu bar

to add the legend to view.

7. To get a better view, you can apply filters. Right-click on Watersaturation, and select Create 1D filter.

8. In the dialog, use the slider to select a minimum water

saturation of 0.35. Click Apply, and observe the change in the




3D window. Click OK to close the dialog.

9. Go to the Input pane, open the Filters folder and turn off the

filter you just made.




Using I, J, and K filters in a 3D window

There is a wide range of available filters you can use when you are

viewing data in 3D.

Exercise steps1. Continue to work with the 3D window displaying the water

saturation.

2. To make the I, J, and K filters available, activate the Definesimulation case process from the Processes pane.

3. Click the Display the cells with same K button to view

one K-layer at a time.

4. You can use the Step property forward/backward buttons

/ to go to another K-layer.

5. Click once more to cancel the K-layer filter.6. Click the Toggle simbox view button to change to a view

that flattens the model.

Making filters using a Histogram window

You can make a filter based on data displayed in a histogram or a

function window. The filter can be applied to data displayed in a 2D or

3D window.

Exercise steps

1. Open a histogram window, and display the initial pressure2. Click the Select using 1D range on x-axis button in the

function bar.

3. Left-click in the histogram window and drag to select the

values that should define the filter. Select only the largest

pressure values to create a filter that exclusively displays the

cells with high pressure.




4. Go back to the 3D window that displays the water saturation.

5. Go to the Input pane and expand the folder Filter folder >User.

6. Select the Pressure filter, and observe the effect in the 3Dwindow.




View data on an intersection plane

You can insert a general intersection into the model and select to view

data on it. The plane can be moved and tilted.

Exercise steps1. Use the 3D window displaying the water saturation, but turn

off all filters.

2. Right-click the Intersections folder under your 3D grid

(Simple) and select Insert general intersection.

3. Click the Clip in front of plane button in the Generalintersection player toolbar at the bottom of the user

interface.

4. To view data on the plane, click the Toggle visualization onplane button on the intersection plane toolbar.

5. Items that you can display on the plane now have a blue box or

a radio button. Select the box in front of Water saturation to

view the saturation on the plane.

6. Click the Manipulate plane button in the function bar to

move the plane to a different position.

7. Right-click the General intersection on the Models pane

and select Create intersection window.8. Select to display the water saturation in the intersection

window.

9. Select to tile the intersection window and the 3D window by

selecting Tile vertical from the Windows menu.

10. Move the intersection plane in the 3D window and notice how

the intersection window is updated simultaneously.




Optional Exercise - The multi-value probe

Sometimes it is useful to be able to view several property values in the

same grid cell. The Multi-value probe gives you a tabular view of the

grid properties.Exercise steps

1. Return to your 3D window that displays the water saturation

and select to view the pressure.

2. Now you have an access to the Multi-value probe mode

button in the function bar.

3. In the dialog that opens, add four rows by clicking the Append

item in the table button .

4. Use the blue arrow in front of each row to drop the property

into the dialog. Start with porosity from the fine grid.

5. In order to use the grid properties from the simulation results,

simulation case need to be provided (see Input part of the

dialog). Drop in the Simple case from the Cases pane as

shown in the picture below. In the Results part of the dialog,

drop in Porosity (PORO) from the Static sub-folder of the

Simulation grid results. Then, from the Dynamic sub-folder

drop in Water saturation (SWAT) and Pressure(PRESSURE). Note: these properties were taken from the first

time step.

6. Left-click on any cell in the 3D window and observe how the

table is updated to show the property values in that cell. Note

that you can compare the property values between different

grids by using this tool.




Summary

In this module, it was demonstrated how to initialize a simulation case

and how to inspect the initial 3D grid properties.





Reservoir Engineering Upscaling • 137

Module 5 - Upscaling

Introduction

In this module we will briefly cover how to convert a geological grid into

a simulation grid. Geological grids can contain tens of millions of grid

cells; however, a model that is suitable for simulation usually consists

of 100.000 to one million cells, depending on the computer the

simulations are run on. Consequently, a coarser, less detailed model is

required. In addition, since the simulators are designed to work on

orthogonal grids, the coarse simulation grid should be as close to

orthogonal as possible.

The first step is to coarsen the fine scale grid. To do this, you must first

define the resolution in the x-and y-directions using the Pillar griddingprocess. Afterwards, the subdivision in the z-direction will be made

using the Scale up structure process.

Once the geometry of the coarse grid is defined, we will use the

Geometrical modeling process to quality check geometrical

properties of the coarse grid, such as grid cell volumes and angles.

Finally, the properties from the fine grid will be re-sampled into thecoarser simulation grid using the Scale up properties process.

Prerequisites• Basic knowledge of Petrel is required.

Learning Objectives

In this module you will learn how to:

• Make a coarse simulation grid based on a fine scale grid usingthe Pillar gridding and Scale up structure processes.

• Compute geometrical properties such as cell angles and

volumes for a 3D grid

• Scale up properties from a fine to a coarse grid using the Scale

up properties process



138 • Upscaling Reservoir Engineering

Lesson 1 – Grid Coarsening using the Pillargridding process

1. Coarsen the fine grid in the x- and y-direction

2. Make a vertical subdivision of the coarse grid

3. Quality check the resulting 3D grid (cell angles)

4. Sample properties from the fine grid into the coarse

UpscalingWorkflow

Coarsen the grid in the x- and y-directionSimulation considerations

Cell size and shape• Sufficient detail to describe flow

• Number of cells small enough to run

simulation

Grid orientation

• Permeability anisotropy• Fault directions

Wells

• Enough cells between wells




You may find that there are conflicts between the different

requirements of the simulation model. A description of the reservoir in

sufficient detail, describing changes in saturation and pressure, may

conflict with the maximum number of cells a simulator can do

computations on in a reasonable amount of time. While a geological

model can consist of tens of millions of cells, a typical desktop

computer cannot perform simulations on models with much more than a

million cells.

Making the Coarse GridTwo methods

Make simple grid• Simple and fast• For models without faults

• Can insert simulation faults

Pillar gridding• Used to make 3D grids that adapt to

faults

There are two ways to make a simulation grid using Petrel, the Makesimple grid process and the Pillar Gridding process.

Previously, we made a grid using the Make simple grid process, and

were then able to insert vertical ‘simulation’ faults at the position of

existing grid nodes. Simulation faults can be barriers to flow, but do not

have throw, so they do not create communication between layers. You

can introduce throw along simulation faults using the Edit 3D Grid

process, but this is not recommended as the editing process is very timeconsuming and can be difficult to quality control. Use the PillarGridding approach if you have faults with throw, non-vertical faults or

if you want the faults to define segments in your grid.

The result of both of these processes will be a skeleton framework of

the 3D grid that is ready to insert surfaces into.




Pillar griddingOverview

1. Create a grid adjusted to the mid-points

of the Key Pillars.2. Extrapolate the pillars to the top and

base shape points. This will create a

3D grid of pillars, represented by the

top, mid and base skeleton grids.

Pillars will be

created at

every corner of

every grid cell.

Pillar Gridding - Concept

Pillar Gridding is the process of making the “Skeleton Framework” of a

3D grid that incorporates faults. The Skeleton is a grid consisting of a

Top, a Mid, and a Base grid. Besides the three skeleton grids, there arepillars connecting every corner of every grid cell to each other. In the

above slide, the figure to the right shows an example of the three

skeleton grids and one intersection through the grid that shows the

Pillars connecting grid cells together.

When creating the Pillar Grid, you will work with the Mid Skeleton grid.

The Mid Skeleton grid is the grid attached to the mid-point of the Key

Pillars, which defines the fault planes (left figure). The purpose is to

create a grid that has good geometrical properties at the Mid point

level, with respect to grid cell size, orientation and appearance of thecells. The next step is to extrapolate this Mid Skeleton upwards and

downwards in order to create the Top and the Base skeletons. This is

done when you click OK in the Pillar gridding process dialog.




Pillar Gridding - Terminology

Faults and directions:

Guidance for the grid (optional to set no

fault or set no boundary)

Boundary:

Polygon, boundary segment or part ofboundary

Trends:

Guidance for the grid and used as

segment divider (where no faults)

Segments (Regions):Compartment closed by faults or trends

Segments – (fault compartments) are areas that are enclosed by

faults, grid boundary, trends or any combination of these. Segments are

used in several processes in Petrel. For instance, different settings and

filtering can be applied to segments, and volumes will be reported by

segment when running the Volume calculation process. Segments are

similar to the term ‘Regions’ used in ECLIPSE. Segments can be used to

create different Fluid in Place Regions with different contact levels andfluid properties.

Boundary – The boundary defines the extent of the model. You can use

a polygon as input, or you can digitize the boundary. Faults can be set

as part of the boundary.

Trends – Trends can be used to orient the grid cells in a particular

direction. Trends can be set outside of the grid to give an overall

direction for the grid cells. The trends can define both I and J directions.

Trends can also be used to connect one fault to another or they can be

inserted between faults. Trends cannot cross faults. Trends can be usedinside the model to separate areas into different segments.

Faults – An area enclosed by faults will, by default, make out a

segment of the model. If a direction is assigned to a fault, the grid is

forced to be aligned with that fault.




Pillar griddingCell shape

Make zig-zag type faults

Gives a grid with cell angles close to

90°.

Simulators assume right angles at cell

corners.

Pillar Gridding - Settings

• Give a name to the model or overwrite an existing model.• Enter the increment in I and J. The increment is given in

project units.

• If you are making a simulation grid, define zig-zag type of

faults. As a general rule, the deviation from 90° should be less

than 25 –30°, and the average less than 15°.

• Once all of the settings are entered, click Apply. This will

create the Mid skeleton grid.

• When the Mid skeleton grid looks good, click OK and the

pillars will be extrapolated upwards and downwards in order

to create a Top and a Base skeleton grid.




Use trends OUTSIDE the boundary to

get zig-zag faults AND the correct

grid orientation, or set the orientationin the process dialog.

Use zig-zag faults

To create a simulation grid with

orthogonal cells, the number of trends

and directed faults in the grid should

be kept to a minimum.

Pillar griddingCell shape and orientation

You must choose whether some faults should define a direction in the

grid. For a simulation grid, the fewer the better, as this will allow thealgorithm to make orthogonal cells. The default grid orientation is

North-South. To change this without making a fault into a directional

trend, create a trend outside the area of the grid. By doing this, you can

give a direction to the grid, and still ensure that all faults are zig-zag.

Alternatively, go to the Expert tab on the Pillar gridding process

dialog and specify the rotation angle.




Pillar griddingCell size

I and J increment

Gives the average cell size, and hence

the model size

The cell size specified is an average –

cells will vary in size as the gridding

honors faults

One of the many aspects to consider when setting cell size is the effect

of numerical dispersion. Numerical dispersion is due to the

discretization of the volume into cells with properties at the center.Water is injected into Cell 1 and as soon as the critical water saturation

is reached, water will be able to move to Cell 2. Once water is mobile,

it will advance in every time step, no matter the length of the time step.

This creates a smeared out water saturation front, instead of the

correct sharp displacement front. One way to reduce the effect is to

have smaller cells.

If the model contains cells with a small volume, this could cause the

time required for the simulator to increase. It is possible to select to setsuch cells inactive. If the total volume of all such cells is significant,

consider redoing the gridding.




Throughput related problems

You can set a threshold value for pore

volume. Cells with a smaller pore

volume will be set inactive.

Once your simulation case is initialized, the pore volume property isstored in the Static sub-folder of the Simulation grid results folder

on the Results pane. If this property shows that you only have a few

cells with a small pore volume, you can select to set those cells inactive

to avoid throughput problems and increased simulation time.

Select the Advanced>Transmissibilities tab of the Definesimulation case process and type in the minimum pore volume. On

this tab, you can also set max pinch-out thickness for no-neighbor

connections to be generated.

Notice that the export of transmissibilites and minimum pore volumes

from the Define simulation case process is not supported by

FrontSim.




Pillar griddingFaults tab

In the Faults tab:

1. Select Selected faults/trends

2. Deselect All faults

3. Select/deselect faults in list

4. Click Update visible from lists

You can select to remove faults

Faults can be excluded from the Pillar Gridding process by turning

them off on the Faults tab of the process dialog. You must click the

Update visible from lists button to see the effect in the 2D window.

Pillar gridding

Pillar geometry and grid formats

Select a simple pillar geometry for

simulation grids

Five types of geometry files can be created

for simulation:

.OPF – most flexible, incl. curved faults,

binary

.GRID – incl. curved faults, binary

.EGRID – straight line faults, binary.GRDECL – straight line faults, ASCII

.GSG – incl. curved faults, binary




The more complex the pillar geometry, the more accurately the cells

will honor volumes on either side of faults. However, the cells will be

less orthogonal. Notice that the grid formats GRDECL and EGRID (uses

the ZCORN and COORD keywords) only supports vertical and linear

faults. If you use listric or curved faults in your Petrel project and export

the grid to the simulator in one of these formats, the grid will be

distorted.

Refer to the Initialization lesson in Module 4 for more information on

the grid formats.

Pillar griddingResult

The result of the Pillar gridding is a skeleton grid. The skeleton grid

consists of a top, a mid, and a base skeleton, representing the top, mid

and base shape points of the Key pillars, respectively.Along and between all of the faults are a set of pillars, evenly

distributed based on the given increment in the I and J direction. This

defines the framework, including the faults and the cell size, that the

surfaces can be inserted into. As no surfaces are inserted yet, there are

no 3D grid cells at this stage.




Exercises – Grid coarsening

You are provided with a 3D geological scale grid with properties, which

should be coarsened for simulation purposes.

The Pillar gridding process is a key part of building a 3D grid. This is

where the size and geometry of each cell will be set. The steps outlined

below do not cover all the functionality available in Pillar gridding.

Further information is available in the Online Help.

Exercise Workflow• Make the coarse grid using the Pillar gridding process

• Change grid orientation

Exercise Data

In this exercise, continue to use your project from the previous exercise.

Grid coarsening using the Pillar gridding process

Exercise steps1. Open a 3D window, go to Petrel RE 2010 folder in the

Models pane and display the Fault model.

2. Single-click on the Petrel RE 2010 model (remember to

always click on the icon of an object) to make it active – bold.

Operations in Petrel are done on the active item, not onitems displayed in a window.




3. Double-click on the Pillar gridding process under Cornerpoint gridding in the Processes pane. Ensure the top border

of the Pillar gridding process dialog reads Pillar griddingwith ‘PetrelRE2010/Fault model’. You will be prompted with

a 2D window displaying the faults from the fault model as

illustrated below. Inspect the Models pane and make sure

that only objects from the active model are visualized.

4. You need to specify a boundary for your reservoir. In this

exercise, we will use the boundary that was made for the fine

model. Expand the Fault model and notice that it has a

boundary.

5. In the Settings tab of the Pillar gridding process dialog,

select Create new. Name the grid Upscaled. Change the

Increments to 350x350 m, and select Make zig-zag typefaults.




6. On the More tab, select the Vector field method (utilizes

FloGrid algorithms for I/J assignment).7. In the Geometry tab, make sure Listric and Curved faults are

deselected, both in Non faulted pillar geometry and in

Faulted pillar geometry. This ensures that the final grid will

only have linear pillars.

8. In the process dialog, click Apply. Petrel will attempt to build

the mid skeleton grid with the parameters you have specified

as illustrated below. Note that there is a direction assigned to

one of the faults causing the grid to be directed along that

fault.




Changing the grid orientationOften a specific grid orientation is thought to be better for simulation

purposes. In this exercise, you will learn how to set the grid orientation.

Exercise steps1. To remove the direction from the fault, first select the fault that

is colored green by left-clicking it. Then click the Set arbitrary

direction button in the function bar.

2. Click Apply to see the effect. The grid should now have the

default north-south direction.

3. To change the orientation of the grid, simply insert an I or J

trend line outside the grid using the New I-trend or the

New J-trend button (left-click to start and double-click to

end the trend line). Trends can be deleted by selecting them

and pressing Delete on the keyboard. Click Apply to see the

effect once you have added a trend.




4. When you are happy with the mid skeleton grid, click OK in the

process dialog. Accept the generation of lower and upper

skeleton grids by clicking Yes. Examine these in the 3D

window.


It is possible to only use a sub-set of the faults in the simulation grid

without removing any data from the original Fault model. You canremove faults from the simulation model in two ways:

a. Turn them off in the Faults folder under the Fault model in

the Models pane.




b. In the Faults tab of the Pillar gridding dialog, select Gridwith selected faults/trends. Then, deselect the AllFaults check box. You can now specify which of the faults

in the list you want to include in the 3D grid. Click the

Update visible from lists button to update the 2D

window.

Lesson 2 – Vertical coarsening –the Scale upstructure process

Vertical subdivision

0 1000Permeability, mD

Stratigraphic

Model Sim Model 1Sim Model 2

Simulation results will be different!

Sim Model 3

A fine scale geological model can be represented by models of different

resolution for simulation. It is important for the simulation models to

keep the main characteristics, such as horizontal flow barriers, of the

original model.




Vertical subdivisionTwo methods

Based on input data

Use the Make horizons, Make zones,

and the Layering processes

Based on the fine model

Use the Scale up structure process




There are two ways to subdivide the simulation grid in the vertical

direction.

Based on input data – Use the Make horizons, Make zones,

and the Layering processes to do the subdivision based on theavailable input data such as surfaces, seismic interpretations,

and isochore data. This type of vertical subdivision is usually

done as part of the geological structural modeling process;

further details are covered in the Structural modeling course.

Based on the fine model – Use the Scale up structure process

as shown in the illustration on the slide. In this case, a fine grid

is given as input to the process and then the layering of the

simulation grid is done by using information on the layering of

the fine grid. This procedure will be explained in the following

slides.

Scale up structureSettings for each zone

Specify the number of layers in each

zone.

Specify the type of layering in each

zone.

You can combine two zones intoone by clicking

Remember to update the Top and

Base horizon of your new zones.

Settings for each zone - Once a fine scale model is inserted into this

interface, the bottom panel is populated with the vertical layering

scheme of the fine model. You must then do the required edits to

produce a coarser vertical layering. Select the settings with great care

to make sure that important features of the fine model are captured,

such as a sealing layer.




In this panel, you also specify the zonation of the coarse grid. It is

possible to combine two zones in the fine grid into one zone in the

coarse grid. To do so, delete one of the rows in the table. Then, insert

the correct top and bottom horizon on the remaining zones by selecting

them in the Input pane and dropping them into the table by using the

blue arrow. For each zone, you must select the type of zone division;

proportional, follow base, follow top, or fractions. Finally, specify the

number of layers or layer thickness within each zone.

After the grid is built, and before the properties are upscaled, the grid

geometry should be checked. Cells which deviate considerably from

orthogonal, have small volume cells next to large volume cells and

badly distorted cells, can have a negative impact on the simulation. If

errors are encountered as a result of poor grid geometry, the simulation

time may increase considerably or may not complete at all.

Use the simulation report to identify problems related to cell geometry.

Cells which cause problems can be set as inactive (ACTNUM=0). If

problems are severe, the grid should be rebuilt.




Cell angles

Cell angles - Where faults have been set as I or J trends, the grid may

become distorted and cells deviate considerably from being orthogonal.

Compute the geometrical property Cell Angle and use the property filter

to identify cells with angles that are far off from 90 degrees. The values

calculated are angles representing the maximum deviation from 90

degrees at each corner. As a rule of thumb, values less than 15 are

good for simulation. Higher values can result in errors when used in a

typical five-point difference scheme. However, distorted cells may not

be so important in regions that are not significant for flow (e.g. inactive

cells or aquifer regions).

Create 1D filters - To get a better view of where a property takes on

values in a particular range, right-click on the property and select

Create 1D filter. Use the sliders to specify the values you want to filter

out. The new filter is stored in the Filter folder of the Input pane.

Remember to select

Create new property if you

are running the

Geometrical Modeling

process to create several

new properties. Petrel will,

by default, select to

overwrite an existing

property.




Cell inside-out

Cells close to faults may become so distorted that they sometimes can

turn ‘inside out’, where one axis is pushed through a different face.These generally do not visualize well, but can be isolated by using the

property filter to remove the cells which deviate from 0 (normal). The

cell inside-out check just gives a flag to indicate errors. If it is zero

everywhere, the grid is OK.




Exercises – Vertical coarsening and grid qualitycheck

In the previous exercise, you specified the coarse grid layout in the

x- and the y-direction. The next step in the coarsening process is tospecify the vertical subdivision. In this exercise, the layering of the

coarse grid is done based on the layering in the fine grid using the

Scale up structure process.

After the grid has been subdivided in the vertical direction, you can

check the geometry of the grid cells by computing cell angels and

volumes.

Exercise Workflow• Use the Scale up structure process to specify the layering of

the coarse simulation grid based on the layering of the finegrid.

• Check the geometry of the resulting grid, in particular check for

bad cell angles and twisted cells.

Exercise Data

In this exercise, continue to use the project from the previous exercise.

The Scale up structure processThe layering should be done with care. Do barrier layers in the fine

model need to be kept as separate barrier layers in the upscaled model,

or can you combine these into a thick layer together with other layers?

How can you preserve the lateral and vertical heterogeneities?

It is important to keep the fine model (the geology) characteristics. This

is done by keeping more of the layers separate. However, it will always

be a compromise between fewer cells and keeping the level of detail.

Exercise steps1. Make sure the upscaled grid you created in the Pillar

gridding process is active (bold) by clicking on its name.

2. Double-click the Scale up structure process in the

Upscaling folder of the Processes pane.

3. Expand the Petrel RE 2010 model and click on Fine grid.




4. Click on the blue arrow in the Scale up structure processdialog to insert this grid as the Input grid. When this is done,

the layering in the fine scale model is displayed in the lower

part of the window.

5. There are three zones in the input grid. We are going to specify

two zones in the coarse grid. Left-click on the symbol in front

of Zone 1, then click the Delete selected row button.

6. Rename the two remaining zones Top and Base, respectively.

7. Go to the Models pane, select the Top reservoir horizon

under the Horizons folder of the Fine grid, and drop it in as

the Top horizon of the zone Top.

8. Select proportional layering for both zones.

9. Select to use 5 layers in the Top zone, and 3 layers in the Base

zone.10. Press OK to run the process.

11. Select to view the Edges of your Upscaled grid in a 3D

window to see the resulting layering. Save the project.

Grid quality checkQuality checking of the grid should be a continuous process during the

upscaling process. This includes checking the grid for cells with small

volume or with angles that deviate too much from 90 degrees.

Exercise steps1. Activate the upscaled grid (make it bold). Petrel processes




apply to the highlighted grid, which may not necessarily be the

same as the one displayed in the 3D window.

2. In the Processes pane, open the Property modeling folder

and double-click on Geometrical modeling. The process

dialog header (at the top of the process dialog) shows which

3D grid you are working on.

3. Ensure Create new property is selected.

4. Use the drop-down list Select method to select the method

Cell Volume. Accept the default property template.

5. Click Apply. You now have a new property called Bulkvolume in the properties folder in your active 3D grid. The

property gives the bulk volume for each individual cell.

Right-click on the Bulk volume property, select Settings and

inspect the Statistics tab to check for negative/small cellvolumes.

6. Repeat the two steps above with Cell Angle and Cell InsideOut as the method. Remember to select Create newproperty each time and to select an appropriate template. The

Cell Angle property gives the deviation from angles of 90

degrees for each cell. If the Cell inside out property is

different from zero, the cell is twisted.

7. Examine the new properties located in the Properties folder

in a 3D window. You may need to reset the color scale. First

select to view the color legend by clicking the Show/hideauto legend button in the top tool bar. Then, click on the

Adjust color table on selected button .




Using value filter

You can filter the grid on properties to see only cells with extreme

values for each of the geometrical properties.

Exercise steps1. Display the Cell angle property in a 3D window.

2. To create a value filter, right-click the Cell angle property and

select Create 1D filters.

3. Use the sliders to make a filter where you only see the largest

values.

4. Click Apply.

5. Go to the Input pane. Note that you can turn the filter on and

off from the Filters folder. Save the project.




Lesson 3 – The Scale up properties process

1. Coarsen the fine grid in the x- and y-direction

2. Make a vertical subdivision of the coarse grid3. Quality check the resulting 3D grid (cell volumes, cell angles)

4. Sample properties from the fine grid into the coarse

UpscalingWorkflow




Scale up properties

Select the property or the folder ofproperties to scale up by left-

clicking in the Models pane.

Click the blue arrow in the Scale

up properties process dialog to

drop in the selected property.

You need to select the properties to scale up. You can select anyproperty from a Properties folder on the Models pane, not only from

the grid that was used for the structural upscaling. Multiple properties

can be scaled up in one run.




Scale up properties

Expand the fine grid inside the Scale upproperties process dialog.

You can scale up many properties in one go.

Once you have selected the properties to scale up, a folder for eachinput grid is add to the process dialog. To access the settings for each

property, you need to expand the folder for the 3D grid, and then

left-click the property.

The coarse grid cells to populate can also be restricted by enabling the

Upscale to filtered cells only option. This will restrict upscaling to

those output grid cells, which are included in the currently active filter.




Scale up propertiesSelect algorithm for each property

Left-click one of the properties from the fine

grid to access the settings available.

An algorithm must be selected for each property. Left-click each of the

properties to make it active. Then, select an algorithm from the

drop-down menu.

For scalar properties there are three algorithms to select from:

Averaging (volume-weighted) – This algorithm computes an

average of the property value of the fine grid cells, using the volume of

each cell as weight.

Averaging (cell count) – This algorithm computes an average of the

property in the fine grid cells with the same weight on each input cell

no matter its size.

Summation – Computes the sum of the property value in all fine grid

cells that contribute to the value of a coarse cell. This method should

only be used to scale up volumes.

In addition to those three algorithms, there are two more available to

scale up permeability:




Directional averaging – Gives the user the possibility to use different

averaging methods in different axis directions.

Flow-based upscaling – This is an algorithm where a flow simulation

is run over all fine cells making out each coarse cell to estimate thetotal permeability in each axis-direction of the coarse cell.

Scale up properties

Several methods available for each algorithm

Averaging methods

For all continuous properties, select between the methods:

• Arithmetic mean - Used for additive properties such as

porosity, saturation, and net/gross. ∑=

=n

i

ia xn

x1

1

• Geometric mean – Normally a good estimate for permeability.

It is sensitive to lower values: in n

i g x x 1=∏=

• Harmonic mean – Gives the effective vertical permeability if

the reservoir is layered with constant value in each layer. It is




sensitive to lower values:

∑ =

=n

ii

h

x

n x

1 1.

• RMS (quadratic mean) -∑ =

=n

i ir xn

x1

21

.

• Minimum – selects the lowest value.

• Maximum – select the highest value.

• Power – The user must specify the power ‘p’. If p=-1, this

method is equal to harmonic mean, if p=2 it is equal to RMS.

pn

i

p

ir xn

x ∑ ==

1

1

For discrete properties, the choice of algorithms is different:

• Most of. Assigns the value that occurs the largest number of

times.

• Minimum. Assigns the minimum value.

• Maximum. Assigns the maximum value.

• Arithmetic. Computes the arithmetic mean.




AlgorithmPermeability – directional averaging

Input: Specify each of the input

components. Those can all be the same.

Output: Three permeability components.

Directional averaging methods for permeability

Permeability is different from other grid properties in the way that the

value in a cell is dependent on the value in neighboring cells. Therefore,there are more methods available for permeability than for other

properties.

• Arithmetic-harmonic – for each coarse grid cell, the fine cells

in each plane perpendicular to one of the axis direction are

arithmetically averaged to give an approximate permeability

for that plane. The plane permeabilities are then harmonically

averaged to give the permeability for the coarse grid cell in

that axis direction. This is repeated for each of the I, J and K

directions to produce the three different output permeability

properties.• Harmonic-arithmetic – This method works in the same manner,

only in this case the harmonic averaging is computed first, then

arithmetic.

• There is also Arithmetic-Power, and Power arithmetic. These

methods work as the two methods explained above, only

power averaging is used instead of harmonic.




Note that harmonic mean gives more cells with low values than

arithmetic mean does. Therefore, harmonic mean is commonly used to

upscale permeability for which it is important to capture cells with lowvalues.

Exercises – Scale up properties

In the previous exercise, you completed the 3D grid. In this exercise,

you are going to sample properties from the fine grid into the coarse

grid. To do so, you need to instruct Petrel on which fine grid to sample

properties from. You also need to specify which properties to re-sample

and by which upscaling method. There are several averaging methods

available in Petrel. Each method gives you a slightly different result. Forinstance, a harmonic mean puts more weight on small values than an

arithmetic mean does. Flow based upscaling will assign permeability in

the upscaled grid that reflects the flow in the fine grid.

Finally, you must tell Petrel which of the layers in the fine grid should

contribute to each of the layers in the coarse grid.




Exercise Workflow• Select which grid to sample properties from

• Specify which layers in the fine grid should contribute to each

of the coarse grid layers when properties are upscaled• Select which properties to scale up and by which method

• Quality check the results

Exercise Data

In this exercise, continue to use the dataset from the previous exercise.

Scale up properties

Exercise steps1. Make sure the Upscaled[U] 3D grid you created is active

(bold).

2. Open the Scale up properties process which is located

under Upscaling in the Processes pane.

3. You need to specify which properties to scale up. Select

Permeability and Porosity from the Properties folder of

Fine grid in the Models pane and drop them into the process

dialog by clicking the blue arrow.

4. Select the Porosity property by left-clicking it.

5. Use Averaging (volume weighted) as algorithm.

6. Select Arithmetic as Method.




7. Left-click the permeability property, and select to use

Directional averaging as algorithm.

8. SelectArithmetic-Harmonic

as the averaging method.

9. Notice that the permeability property has now turned into a

folder in the list in the process dialog. Expand the folder.

10. Select either of the components of Permeability by left-

clicking it.

11. Select the correct input for each of the permeability

components. Use Permeability for the I- and J-direction and

PermK for the K-direction.




12. Click OK to scale up permeability and porosity.

Apply different methods

Exercise steps1. Open the Scale up properties process again.

2. Notice how the settings for the properties that you have

already upscaled are preserved and listed in the process

dialog.

3. Also, notice how the Calculate setting is deselected. This

means that as you add new properties to the dialog and click

Apply, only the new ones will be computed.

4. Select Permeability and Facies from the Fine grid on the

Models pane and drop them into the process dialog.

5. Left-click on the Permeability property that you just added to

the process dialog.

6. Select to use Averaging (volume weighted) as the

algorithm, and Harmonic as the Averaging method.

7. Enter a name for the new permeability property.




8. Left-click the Facies property.

9. Select to use Averaging (volume weighted) as algorithm,

and Most of as Averaging method.

10. Click OK to scale up the properties.

Review the upscaled properties

Exercise steps1. Open a function window.

2. SelectPermeability_I

(arithmetic-harmonic) andPerm_harmonic (harmonic). Harmonic average will usually honor the

lower values more than arithmetic-harmonic. Observe this

trend in your plot.

3. Open a histogram window and select to view the upscaled

permeability properties along with the fine grid property.




4. When you work with histograms, note that you can toggle

between comparing the number of cells or percentage of cells

by clicking the Use percentage in Y-axis button in the

function bar. It is useful to compare percentage of cells when

you compare values from the fine grid with values in the

coarse grid.

5. Also you can select to volume weight the cells you are viewing

by pressing the Weight histogram with volume button .

Review upscaled properties in a 3D window

Exercise steps1. Open a 3D window.

2. Select to view the facies property on your upscaled grid.

3. Click the Multi-value probe mode button in the function

bar.

4. In the dialog that opens, drop in porosity from both your fine

and your upscaled grid along with the facies property from

your upscaled grid.

5. Left-click both in the channel and floodplain cells and compare

porosity values.

You can make a CDF

-curve (cumulative

distribution function - curve)

by pressing the Showcdf-curve icon or you

can display a line between

the histogram bars by

pressing the Show lines

between the columns icon

. Both tools are in the

Function bar.







Summary

In this module we have upscaled a model from geological scale to a

simulation grid. First, we did the coarsening in the horizontal direction

using the Pillar gridding process. Next, we specified the layering ofthe coarse model using the fine grid layers as input. Using

Geometrical modeling, we checked the coarse grid for poorly shaped

and small cells. Finally, properties were scaled up to the coarse grid

from the fine grid.





Reservoir Engineering Local grid refinements and Aquifers • 179

Module 6 - Local gridrefinements and Aquifers

Introduction

In this module, you will learn how to add local grid refinements and

aquifers to your simulation model. Aquifers are used to model the

pressure support from water or gas on the edge of a model. In Petrel,

such processes are modeled using the Make aquifer process. It is

useful to refine the grid in areas of fast flow, and this feature is

available through the Make local grids process.

Prerequisites

Basic knowledge of Petrel is required for this module.

Learning Objectives

In this module, you will learn how to:

• Add local grid refinements• Model aquifers



180 • Local grid refinements and Aquifers Reservoir Engineering

Lesson 1– Local grid refinements

Local grid refinements

To better model fluid flow behavior, local grid refinements allow for afiner resolution of parts of the 3D grid. Transmissibility between the

local grids and the global model are computed automatically by

ECLIPSE/FrontSim. The properties of the cells in the refined grid cells

can be inherited from the global grid or specified explicitly for the

refined cells.

The Make local grids process is available from the Corner pointgridding folder in the Processes pane. Local grids are defined using

wells, surfaces, and polygons as input.




Local Grid Refinements

Choose to create a new LGR set or

edit an existing LGR set.

A set contains a number of local

grids.

Each set is stored as a folder on

the Models pane.

The areas that should be refined can be selected using:

Wells: You must specify a radius. All cells that have their center closer

to a well than the specified radius are refined.

Polygons: Petrel computes the vertical Z-projection of the polygon with

the host grid and selects all of the cells in the uppermost layer whose

centers lie within the polygon. The polygon must be closed. This set of

cells is then projected down through the layers (K-index) to produce a

cell set.

Surfaces: When surfaces are used as input to the Make local grids

process, the cells that are refined are found by examining the distances

between the cell-centers and the surface in a direction normal to the

surface and around the edges. If the distance is less than the source

influence distance, the host cell is added to the set.




Specify host cells from sources

Host cells

Select the sources:

Wells: Make a refinement around the

well.

Polygons: Make a refinement inside

the polygon.

Surfaces: Make refinements above or

below.

Click the blue arrow to add sources to

the gridding process.

Refinement Method

Select a source or folder of sources in the

source list, and then select refinementmethod.

Cartesian : Give number of fine cells inside

each coarse cell

Cartesian Gradual : The coarse cells are

refined gradually. Finest resolution in the

middle. Give number of levels.

Illustration: Cartesian gradual refinement

with 2 levels.




Cartesian Nx,Ny,Nz: You specify the number of subdivisions required

in each grid direction (Nx, Ny, Nz) and each host cell in the host cell set

is sub-divided equally.

Cartesian Dx,Dy,Dz: You specify the maximum size of the subdivisionsrequired in each grid direction (Dx, Dy, Dz). Each host cell in the host

cell set is sub-divided equally using the closest value to that requested.

Cartesian Gradual Nx,Ny,Nz: Similar to the Cartesian Nx,Ny,Nz

method, except that Petrel gradually increases the refinement degree

towards the local-grid source over a number of levels specified in

Levels. The parameters Nx, Ny, Nz thus represent the target number of

subdivisions (in each grid direction) within the highest-refinement level

(i.e., closest to the source). The method is available when surfaces or

wells are given as input.Cartesian Gradual Dx,Dy,Dz: Similar to the Cartesian Dx,Dy,Dz

method except that Petrel gradually increases the refinement degree

towards the local-grid source over a number of levels specified in

Levels.

Set source parameters

Select a source or folder of sources in the

source pane, and then set the selectionparameters.

Zone and Segment filters: Limit the

refinements to some zones/segments.

Grid separate zones: Creates a separate

local grid in each zone.

Source influence distance: Distance from

well or surface that is refined.

Click the Display host cells button to see

the cells in the 3D viewer that will be selected

for local gridding.




Zone filter: You can select which zones should be included for grid

refinement. This selection is also used when Grid separate zones is

selected. Similarly, you can use the Segment filter to only generate

grid refinements inside some of the segments.

Grid separate zones: Non-gradual refinement methods only. Select

this if you want to create separate local grid sets for each zone.

Use active filter: Select this if you want to restrict the local grids to

the host grid cells that are currently displayed.

Extending host cell along I, J, K

The local grid can be made more or

less regular in shape by extending it

along the I, J, or K direction

An extended grid may have:

• Fewer surface cells – thus, fewer

connections to the coarse grid.

Less work for the simulator.• More cells in it – the more cells,

the more work for the simulator

No extension

Extended in K

When local grids are exported to the ECLIPSE simulators, they are

decomposed into cuboids (in I,J,K). You can reduce the number of

cuboids by extending a host cell set in any, or all of the I, J or K grid

directions. This will generate larger host cell sets, but fewer cuboids intheir decompositions. You must choose between these issues so that it

generates an acceptable simulation.




Grid to well connections

Only cells with connections are refined

Choose this option for a selected well if you want to restrict the active

source to open well–grid connections only (for example, perforations

and open-hole sections).




Set different parameters for different sources

By default, cell selection and

gridding parameters are the same

for all sources.

The source panel displays a

summary of the parameters for

each source.

To change settings:• Select a source

• Deselect Use default

• Specify individual settings




The two images above illustrate that a local grid cell gets the same

property value as the coarse cell. This does not apply for geometrical

properties such as cell volume or cell angle.

Upscale properties

If the Use property filter option

is on, Petrel will only upscale

onto the grids that are visible.

• Select property in the fine grid

• Display only the local grid

• Use property filter

• Deselect Ensure all cells get values

You can use the Scale up properties process to scale up a property

onto the local grid set. To do so:

• Display a property in a 3D window

• In the Models pane, deselect to view the Global grid so that

only the local grid set is displayed

• Open the Scale up properties process and select which of

the fine grid properties to scale up

• SelectUse property filter

and deselectEnsure value in allcells




Grid coarsening

1. Use polygon

2. Select generation method – Coarsen

3. Specify settings

Cells can be amalgamated to reduce the total number of active cells inthe global grid. Coarsening sets must not overlap one another, but they

can be joined together.

Local grid refinements cannot be placed within or adjacent to a grid

coarsening; that is, the local grids can only be applied to non-coarsened

cells.

Petrel sends the original fine model to the simulator together with the

generated geometry for grid coarsening (COARSEN keywords).




LGR - Export

1. Make the local grid set active (bold)

by clicking on its name.

2. Right click the global grid set and

select Export…

By default, properties do not get exported

with LGRs. ECLIPSE will apply host cell

properties to LGRs.

To export a local grid set, it must be highlighted (bold). It is not

necessary to display the local grid set.

Local grid properties are not exported explicitly; ECLIPSE will read the

local grid keywords and apply the host cell properties.

The export formats that support local grid refinements are:

• Open Petrel Format (OPF) (Binary)

• GSG (Generic Simulation Grid)

• ECLIPSE Grid keywords (grdecl) (ASCII)

• VIP Grid keywords (grdecl) (ASCII)

The CARFIN keyword is exported to set up a Cartesian local grid

refinement. It specifies a cell or a box of cells identified by its global

grid coordinates I1-I2, J1-J2, K1-K2 to be replaced by refined cells. The

dimensions of the refined grid within this box are specified as NX, NY,

NZ.




Exercises– Local grid refinements

Local grid refinements allow for a finer grid resolution near wells or in a

region to better model fluid flow behavior. The Petrel workflow permits

you to create local grid sets inside polygons, around wells, and close toa surface. The Define simulation case process only allows you to

include one Local grid set, so all local grids required for the simulation

need to be within this set. You can return to the Make local grids

process and add or remove local grid definitions as required.

Exercise Workflow• Import a polygon

• Make a local grid set

• Inspect the local grid set

• Optional – Upscale property to the refined gridExercise Data

In the following exercise, we will continue with the project we made in

the previous exercises. Or you can use backup project Module_5_Completed.pet.

Import a polygon

Exercise steps1. Right-click in the Input pane and select Import(on tree) and

import the file ImportData>Local grid>LGRpolygon. Make sure

the file type General lines/points (ASCII) is selected.

2. Click OK in the dialog.

3. In the Input data dialog: select Generic boundary polygon

as Line type, then click OK. The polygon appears at the


Make a local grid set

Exercise steps1. Activate your upscaled 3D grid.

2. Expand the Corner point gridding folder in the Processes

pane.

3. Double-click on the Make local grids process.

4. Make sure Create new is selected.

5. In the Input pane, expand the Wells folder, then expand the




Producers folder. Select the wells P03, P04, and P05 and drop

them into the process dialog by clicking the blue arrow .

6. Click the polygon you imported (in the Input pane) and drop it

into the process dialog by clicking the blue arrow .

7. Select the Polygons folder in the Make local grids process

dialog.

8. Select the method Cartesian Dx, Dy, Dz and set Dx/Dy to

100. Set Dz to 10.

9. Select the Wells folder in the Make local grids process

dialog. Select the Cartesian Gradual Nx, Ny, Nz method.

10. Enter a refinement of 3x3x1 and type in 2 Levels for the wells.

11. Select a Source influence distance of 600.

12. Open a 3D window and display the wells, the polygon you

imported, and the porosity property from the upscaled grid.

Select to show the grid lines by clicking the Show/hide grid

lines button in the function bar.




13. Press the Display host cells button in the

process dialog. The grid cells that will be refined are displayed

in the 3D window.

14. Increase the Well influence radius to 800 and click on Displayhost cells again to see the effect.

15. You do not create any refinements until you clcik Apply or OK.

You can continue to experiment with the settings.

16. Select well P05 in the Source name list of the process dialog

and then deselect the Use default check box. Now, you can

adjust the settings for this particular oil producer. Change the

method to Cartesian Nx, Ny, Nz and the Source influence

distance to 500.17. Click OK to generate the local grid set.

Inspect the local grid set

Exercise steps1. In the Models pane, under the active 3D grid, you will now

have a folder called Local grids.

2. Expand the Local grids folder. Right-click on Local grid set 1

and select Settings. Change the name on the Info tab to

Wells and Polygon.3. Click on different properties in the model; note that the local

grids have inherited the host cell properties, with the exception

of geometric properties and simulation results. Geometrical

properties must be computed for the local grid cells, and

simulated properties are only available if the simulation was

run with local grid refinements.

The local grids have

a yellow tick box. This means

they can be used as a filter inPetrel similar to the Zone,

Fault and Segment filters

under the 3D grid. The filter

can also be used with the

Property calculator.





Normally, when you are using the Property calculator, turn off any

local grids under the active grid or turn off the Use filter option in the

Property calculator. Local grid cells will then inherit the propertiesfrom host cells. The local grid cells will display a grey color if they have

not inherited the host cell properties (which is the case if they have

been included in the filter settings in some way).

Upscale property – Optional

In this exercise, you will upscale a property onto the local grid that you

have created without re-upscaling the entire grid. As a result, anycorrections that may have been made to the global grid will not be

changed by this new upscaling run. It is always wise to make a copy of

the properties you intend to update.

Exercise steps1. Click on the porosity property in the Properties folder of your

coarse (upscaled) grid, then use the copy and paste

functionality on the toolbar.

2. Give the new porosity property the name Porosity_lgr.3. Ensure the property Porosity_lgr is displayed in the 3D

window.

4. Deselect to view the Global grid under the Local grids

folder.

5. To scale up the porosity to the local grids, open the Scale upproperties process under Upscaling.

6. Left-click the Fine grid in the process dialog.




7. In the Target cells part of the dialog, select the check box in

front of Upscale to filtered cells only.

8. Left-click the Porosity property in the process dialog.

9. Select Porosity_lgr from the Edit existing drop-down menu.

10. Make sure that Calculate is selected for Porosity_lgr and

that Ensure all cells get value is deselected.

11. For all the other properties make sure Calculate is deselected.

(See tool-tip for more information).

12. Click OK to scale up porosity to the local grid cells.

13. When the process is completed, select the check box in front

of the Global grid in the Local grids folder on the Models

pane.

If you do not want to

upscale all of the properties

from the fine grid to the local

grid (for example, you only

want the Porosity to be

upscaled) be sure that No is

selected in the “Calculate”

column of the Scale upproperties dialog. In this

case, you will upscale only

the Porosity. Compare both

of the porosity properties by

toggling between them. The

only difference should be

between the properties on

the local grids.




Lesson 2 – Aquifers

The illustration shows cells that are connected to an aquifer. In this

case, the aquifer is placed underneath the reservoir and along the grid

edges to simulate pressure support from water.

Make a folder of

aquifers in order to use

multiple aquifers in the

simulation run. The Definesimulation case process

has only one place for

aquifer input.




Make aquifer

Choose to create a new aquifer or edit anexisting aquifer.

Each aquifer model is stored in theAquifers folder on the Models pane

under the parent grid.

Select type of aquifer model

• Numerical

• Carter Tracy

• Fetkovich

• Constant flux

• Constant pressure gas

• Constant pressure/head water

• Rainfall

The Make aquifer process is located under Simulation in the

Processes pane.




Connections

Select model.

Enter area of interest:

Use the Make/edit polygons

process to define the boundary

polygon.

First, specify which model to use. Then, specify the area that should be

influenced by the aquifer. This is done by supplying a closed polygon.

The polygon can be made using the Make/edit polygons process.

You can drop in multiple polygons defining the connection areas of

interest. Each of the polygons have individual settings for creating a

unique drive direction for each area of interest.




Independent polygon areas and drive direction

Use the compass to define drivedirections, the connections the

aquifer will have to the grid.

The direction of the aquifer can be:

• Top down

• Bottom up

• Grid edges

• Fault edges

Fault edges

connection

Bottom up

connection

After the area of interest is specified, you must select the drivedirection and the vertical extent.

If Bottom up is selected, the aquifer is connected to the bottom edge

at the bottom of the reservoir for all cells within the area of interest. In

addition, it is possible to specify the vertical extent.




Use the compass to specify which cells should be connected to the

aquifer.

Aquifer modeling

Numerical

Numerical aquifer - A set of cells in the

simulation grid is used to represent the aquifer.

Their position in the model is irrelevant.

E.g., when Number of cells is 2 - the aquifer is

modeled using two grid cells.

The properties of the aquifer grid cells are set on

the Cell settings tab. Hence the properties of an

aquifer grid cell is independent of its actual

position in the grid.

Numerical aquifers do not connect to local grid

cells.




You can select to use between one to five cells to model a numerical

aquifer. To be able to include a numerical aquifer, Petrel needs the same

number of grid cells that are undefined (for example, outside the grid) or

have zero volume, porosity, or ACTNUM value. These cells cannot be

part of a local grid set.

The properties of the aquifer grid cells are set on the Cell settings tab,

hence, the properties of the grid cells that are used to model the aquifer

do not depend on the position those cells have in the 3D grid.

If the numerical aquifer is modeled using one cell, it is the properties of

this single cell that is used to represent the aquifer. All cells with a

connection to the aquifer is consequently given boundary conditions

depending on those properties. If more than one cell is used, all cells

with connections to the aquifer are given boundary conditions using theproperties of aquifer cell number one, while aquifer cell number one is

attached to aquifer cell number two, and so on.




Fetkovich aquifers can effectively represent a wide range of aquifer

types from the steady state infinite aquifer which provides constant

pressure support to the “pot” aquifer, which is small compared to the

reservoir and whose behavior is determined by the reservoir influx.

The aquifer properties (compressibility, porosity, initial pressure, depth,

productivity index etc.) are set on the Properties tab, and the aquifer

connections to one or more faces of the reservoir are specified on the

Connections tab.

The Carter Tracy aquifer model is a simplified approximation to time

dependent model.

The influence function of a Carter Tracy model is given as tables of

dimensionless time versus a dimensionless pressure, hence, this

aquifer model can be used to model changes in pressure with time. The

default table models an infinite aquifer with constant terminal rate as

given by van Everdingen and Hurst. To supply alternative tables, use

Import (on selection) or Create new function and drop it into

Properties tab of the Carter Tracy model.




Make aquifer Properties tab

Required input depends

on the selected aquifer

model.

The different aquifer models require different input. Refer to the Online

Help manual for details.

Exercises – Aquifers

In this exercise, we will add an aquifer to see whether a better match

can be achieved.

Exercise Workflow• Use the Make/edit polygons process to draw a polygon that

specifies the area that is influenced by the aquifer

• Use the Make aquifer process to add an aquifer to the model

Exercise DataIn this exercise, continue to use the project from the previous exercise.




Add an aquifer

Exercise steps1. Open a 2D window and display one of the horizons along with

the faults of your upscaled grid from the Models pane.2. Activate the Make/edit polygons process from Utilities

folder in the Processes pane.

3. Use the Start new set of polygons (deactivate old) tool

. Draw a polygon which encloses the eastern part of the

model. Use the Close selected polygon tool to close the

polygon.

4. The new polygon is stored on the Input pane. Rename it to

Aquifer boundary.

5. Make sure the Upscaled grid is active on the Models pane.

6. Go to the Processes pane, and open the Make aquifer process located under Simulation.

7. Select Create a new aquifer, and define aquifer model:

Carter Tracy.

8. Rename Aquifer 1 to Carter Tracy.




9. In the Connections tab, select the Aquifer boundarypolygon on the Input pane, and drop it into the Area ofinterest field by clicking the blue arrow .

10. Select Grid edges as Drive direction. Make the compass

connecting to the cell faces from all directions.

11. Under Vertical extent, select a Top limit of -2600 m (the

oil-water contact).

12. Go to the Properties tab, and then select the fluid modelLight oil + gas from the Input pane. Drop it into the process

dialog using the blue arrow.

13. Type in a datum of -1600 m.

14. Click OK to save the aquifer model, leave the dialog open.

15. Display the grid in a 3D window now.




16. Go to the Models pane, you will find newly created aquifer

under the Upscaled grid > Aquifer folder. Toggle the new

aquifer on. The cell faces connected to the aquifer are

displayed in the 3D Window.

17. Now go back to the Make aquifer process, and deselect the

directions between E and S in the compass (see picture

below), then click Apply. Only the cell faces in the greyed

parts of the compass are taken into account for the aquifer

connection. This allows you to filter out the unwished aquifer

cell connections.




Summary

The Make aquifer process was used to model the presence of water

at the edge of the reservoir. How to use The Make local grids

process, which allows you to refine the simulation grid, was alsodemonstrated.



Reservoir Engineering History development strategies • 207

Module 7 - Historydevelopment strategies

Introduction

In this module, you will learn how to set up a development strategy

based on imported observed data. We will also look at how to import

the historically observed production data.

PrerequisitesBasic knowledge of Petrel is required.

Learning Objectives• Import observed data

• View observed data in a function window

• Make a history strategy

• View line data

• Optional: Use the History match analysis tool to view results



208 • History development strategies Reservoir Engineering

Lesson 1 – History development strategies

Development strategies describe to the simulator how a field will be

developed – that is, which wells will produce or inject, at what rates

and pressures they will flow in, what operations will be carried out onthe wells over time, and so forth.

Development strategies make it easy to keep track of how the control

of a field evolves with time. For example, as new wells are drilled, the

target field rates change, wells are converted from producer to injector,

new platforms and manifolds are added and so on.

Furthermore, development strategies make it easy to apply the same

constraint to many wells by using well folders or different values of a

particular constraint to individual wells.

The simulation is normally run in two phases: history match and

prediction.

By using the history match we try to match actual production historywith the simulated history. We use geological, geophysical and

petrophysical input to build a reservoir description, and from those, we

build a simulation model.

Next, we import actual production and pressure information, run the

model, and compare the simulated results with the actual history.






Import observed data

Observed data are imported

using the Well observed data

formatMatch the well name in the file

to wells in your project

To import Observed data (historical data), right-click the Globalobserved data folder and select Import (on selection). Select the

Well observed data file format. The imported data can be used in the

Make development strategy process.





Go to the Data tab to matchproperties on file with a

property identifier in Petrel

On the Data tab, you need to specify the type of data in each of the

columns of the file you are importing. In the illustration, column three

contains the bottom hole pressure (BHP).




Once the observed data vectors are imported, they can be viewed in a

function window. To display observed data, you must select a vector (for

example, oil rate), a well, and the observed dataset on the Results

pane.

User interface

To make a history strategy, you can use the default strategies as a

starting point and then add the features (rules) needed.




Use defaultsA history strategy

Two rules are added:

• Reporting frequency

• History rate control

To create a history strategy using the Use presets button:

1. Make sure that you have loaded the necessary data into the

project – wells, completion events and observed data.

2. Open the Make development strategy process.

3. In the dialog, click on the Use defaults button and selectHistory strategy from the drop-down menu.

The history strategy you just made contains:

• The start and end dates from the first observed data in the

project. These are shown in the strategy tree.

• All the wells in the project. Do not worry if some of them did

not produce or inject in the history – this will be detected on

export to the simulator and the wells are ignored. The wells

are all added to the default group. If you want group reporting,

you will need to reorganize them.• The history rate control rule has been set up with the

recommended defaults for history matching. If needed, change

these in the Rules table. This refers to the first observed data

set found in the project. If you have multiple observed data

sets, and want to use a different one, simply drop the required

set into the rule.




• The report frequency rule has been set to monthly reports, as it

is the most common choice; however, this can be changed.

History strategyEdit default rules

Selecting Oil here, willmake oil the target

rate for the simulation

Drop in the

observed

data

Edit control

modes

Edit time

stepping




In between control changes, regular reports can be output from the

simulator by changing the settings in the reporting frequency rule. By

default, this is added to the first date of every strategy. However, it can

be removed and can be copied to later dates if you want to change the

settings, for example, to report yearly in the early part of a history

match, and monthly in the most recent year.

Plot the observed data versus the development strategy in a function

window.




Data averaging

Imported data is often densly

sampled.

The data is averaged within the

report step in the Developmentstrategy.

The imported data is averaged over the report step length selected in

the Make development strategy process. Plot the observed data and

the development strategy to see how the averaged data matches the

observed data.

Define a history case

Drop the strategy into the Strategies tab

of the Define simulation case process

dialog.




Go to the Strategies tab of the Define simulation case process to

drop in a development strategy. Multiple strategies can be inserted by

first adding a row to the table.

Exercises - Make a history development strategy

Exercise Workflow• Import observed data

• View the imported data

• Make a history development strategy

• View the development strategy data

• Define a simulation case

Exercise DataIn this exercise, continue to use the project from the previous exercise.


In this exercise, you will import observed production and injection data

for the wells in the project.

Exercise steps1. Right-click the Global observed data folder under the Wells

folder in the Input pane and select Import (on selection).2. In the dialog that opens, select the file ImportData>Well_

Engineering>HistoryInj.vol then click Open.

3. In the Import observed data dialog that opens, make sure the

well names in the file matches the correct well in your project.

4. Go to the Data tab.

5. Check that the Column number is correct for the data you are

importing and that an appropriate Property identifier isselected.




6. After you have selected a Property identifier for all the

vectors you are importing, make sure that you select Createnew in the Global observed data column to add a subject to

the Global observed data folder.7. Click OK to import the observed water injection data.

8. Right-click the Global observed data folder under the Wells

folder again and select Import (on selection).9. In the dialog that opens, select the file ImportData>Well_

Engineering>HistoryProd.vol to import the production data

then click Open.

10. In the Import observed data dialog that opens, select the

Merge with radio button to make one observed data set

containing both injection and production data.

11. Go to the Data tab.12. Again, check that the Column numbers and the Property

identifier are correct.

13. Observe that the bottom hole pressure is attached to the

existing Global observed data subject. Click OK to import.




Exercise steps - Visualize the observed data1. Open a function window.

2. Go to the Results pane, expand the Results folder and then

the Dynamic results data folder. Expand the Source data type folder. Select the check box in front of Observed data.

3. Expand the Identifier folder and then the Wells folder to see

all of the wells. Select to view well P04.

4. Select the check box in front of Oil production rate in the

Rates folder along with Bottom hole pressure in the

Pressures folder. Leave the Function window open.




Make a history development strategy

In this exercise, you will create a history strategy using the Makedevelopment strategy process. You will see that the process

automatically selects the imported observed dataset you imported.Exercise steps

1. Expand the Simulation folder in the Processes pane and

open the Make development strategy process.

2. Select Create new development strategy.

3. Click the Use presets button, and select History strategy

from the drop-down menu.

4. Name the new strategy History.

5. On the Strategy tree, set the start date and the end date for

simulation, 2005-02-01 and 2009-02-01, respectively.

6. Find the Rules folder in the Strategy tree (the left pane of the

Make development strategy process dialog) and click the

History rate control (Wells folder) rule. Note that the

observed data set and the wells have been insertedautomatically.

7. Make sure the Production control mode is set to Reservoirvolume.

For the Reporting frequency rule, leave the report frequency to the

default every (1) month.All dates are entered

in the format YYYY-MM-DD,

as recommended by the SPE

standard.




8. To save the history development strategy, click OK.

9. You will find the new Development strategies folder at the


View the development strategy dataIn this exercise, we will examine and compare the history development

strategy to the observed data in a function window.

Exercise steps1. Return to the function window and make sure you have

selected the following from the Results pane: well P04, Oilproduction rate, and the Observed data.

2. Add Development strategies in the Source data typefolder to view in the window. You should now see your

development strategy data and your observed data. Since theyboth are monthly, there should be no difference.

3. Reopen the Make development strategy process, and

change the Reporting frequency rule to every three months

and click OK. You can now see a difference between the

averaged development strategy data and the observed data.




Add a rule to limit the production pressures

It is possible to add a rule to the history strategy to limit the allowed

bottom hole pressures.

Exercise steps1. Open the Make development strategy process.

2. Select your History strategy in the Edit existing

development strategy drop-down menu.3. Click the Open ‘Add rules’ dialog button .

4. In the dialog that opens, left-click the History pressure limit rule, then click Add rule.

5. Use the arrow to drop the Wells Folder from the strategy

tree (not from the Input pane) into the new rule. Enter a

Minimum production BHP limit of 110 bar and a Maximuminjection BHP limit of 380 bar.

6. Click OK to save the changes and to close the dialog.




Define and run simulation cases

In this exercise, we will define and run simulation cases using the

history development strategy we just created. We start by running a

case on the simple 3D grid that we initialized earlier.Exercise steps

1. Open the Define simulation case process and select to edit

the Simple case.

2. Open the Strategies tab, and add a line to the table by

clicking the Append item in the table button . Drop in the

History development strategy that you just made by selecting

it in the Input pane and clicking the blue arrow.

3. Click Apply to save the changes and then Run to run the case.

We will now define and run a case based on the Upscaled 3D grid thatwe made in the upscaling exercises.

Exercise steps1. Open the Define simulation case process and select to

create new case and give it name, Basic.

2. Change the grid from Simple to Upscaled. Make sure the

Simulator is set to ECLIPSE 100.

3. Go to the Grid tab. Make sure you insert the properties you

want to use for simulation. Expand Upscaled grid [U] under

Models pane. Open the Properties folder and drop

Permeability and Porosity into the Grid tab. To be able to

use the blue arrow, you have to select the check box in front of

it .

A message log will

be shown while the

simulation is running.

Information on completion

thresholds is printed on the

message log. The completion

threshold can be changed in

the Settings for global

completions. This will be

covered in the chapter on

completions.




4. Go to the Advanced tab. Make sure GRDECL export format is

selected on the Advanced grid sub-tab. (See tool tip for more

information). Click Apply to save the changes.

5. You are now ready to run your simulation case. Click Run.

Exercise steps

In this exercise we will create a case, which include local grid

refinements.

1. Open the Define simulation case process and select to

create new case and give it name: NoAquifer.

2. Go to the Grid tab. Drop in the local grid set (Wells andPolygon) from the Models pane.

3. Click Apply to save the changes, and Run to run the case.

Five types of

geometry files can be

created for simulation:

.OPF – most flexible, incl.

curved faults, binary

.GRID – incl. curved faults,

binary

.EGRID – straight line faults,

binary

.GRDECL – straight line

faults, ASCII

.GSG – incl. curved faults,

binary




Next, you will define a simulation case where an aquifer is used in

addition to the local grid refinements.

Exercise steps

1. Open the Define simulation case process.2. Select the case NoAquifer that you made in the previous

exercise from the drop-down menu.

3. Select Create new case, and name the new case Aquifer.Note that all settings from your case are preserved.

4. Go to the Grid tab. Add a row to the table .

5. Use the drop-down menu to select Aquifer. It is located at the

bottom of the list.

6. Select the Aquifer (Carter Tracy) from the Models pane and

drop it into the process dialog.

7. Click Apply to save the changes and Run to run the case.

The next lesson will focus on viewing line data.








Function window - settingsCustomize axis display

Adjust settings in the Axis

tab to get the desired plot

layout.

Navigate to the Axis sub-tab of the Settings dialog of the function

viewport to change the appearance of the axis. Here, you can specifythe size of the annotations, the number of ticks, and axis labels.

Similarly, you can open the settings for the Header or the Legend and

do your edits.




Results paneCategorize results

Right-click on Dynamic data and

select Categorize results.

Use the Reset categorize to getback to the default configuration.

The Results pane can be organized in different ways. Right-click the

Dynamic data folder and select Categorize results to change toanother layout. Select the Categorize results option again. This will

sort the data by phase.




Results paneFilter results

Right-click a vector, an identifier or a source

type and select Filter results tree. Now, only

data relevant to your selection is shown.

Right-click the Dynamic data folder and

select Cancel tree filter to cancel the

filter.

The Results pane can contain a large number of vectors. If you onlywant to list vectors that contain data for a specific well or a particular

simulation case you can right-click this subject and select Filterresults tree.




Results paneExport simulation results

Select :• Result vectors

• Identifiers

• Case

Right-click the Dynamic data folder and select Export to export linevectors. In the Export dialog that opens, you must specify a file name

and format. The only format available is Petrel Summary Data where

the columns are separated by tabs.

In the next dialog that opens, you can make a selection of result

vectors, identifiers, and cases for export.




Plot window

A plot window can be used tocombine several view-ports.

A plot window is opened by selecting New plot window under

Window on the menu bar.

Use the New object in window tool to add new view-ports. You

can combine several view-ports of the same type, or as in the

illustration, you can combine different types.




Well section window

You can display a simulated

property (such as oil

saturation) through time for a

selected well.

If you hold your mouse over a

well section, the value of that

property will appear.

3D Viewing

Summary data

1. Display relevant wells from the Input pane.

3. Select : Disc, Sphere, Stack or Bars0

2. Go to settings for Dynamic data.

4. Specify vectors to display from Dynamic

results data.

5. Check the proper Identifier.

Use the time player




The user can display summary data, for example Oil production rate in

3D and 2D windows. The summary vector can be displayed as a disc,

stack, bar or sphere and the size represent the magnitude of the vector.

The display can be animated through time.

Bubble mapsTime varying data

Display time varying data such as

production rates as bubble maps

• Insert new map window

• Select result vectors from the

Results pane

• Select simulation case from

Cases pane

• Play time with the time player

toolbar

Bubble plots can be displayed for observed data, development

strategies, and simulation data. Use the time player at the bottom of

the user interface to go to the time step of interest.




3D Viewing

Streamlines

Streamlines are stored in the

Streamlines folder at the bottom of the

Models pane.

In the settings panel of the streamlines,

you can change the color and the

thickness of the streamlines.

If FrontSim was selected as simulator, a Streamlines folder is added

to the grid folder on the Models pane when the simulation is finished.

Different attributes can be visualized on the streamlines, such assaturations, pressure, and travel times.




3D Viewing

Streamline filters

Use the Startwell or

Endwell filters to view

streamlines from/to

particular wells.

The Startwell filter is useful for displaying all of the wells that are

supported by an injector. Similarly, the Endwell filter is used to display

all of the injectors that support one producer.

Exercise: Change the line style in functionwindows

By default, simulated data is plotted with a solid line, developmentstrategies are plotted with a solid line with points, and observed data is

plotted as circles. The line color is selected automatically, however, you

can override those defaults.

Exercise steps1. Continue to work with the function window that you used in

the previous exercise. Or display any plot data from the

Results pane.

2. Double-click on any of the lines in the plot to open the

Settings panel for the line data.3. To access the settings for one of the lines, select the line in the

list at the left of the Settings panel by left-clicking it.




4. You can now edit the line and point styles by using the bottom

right part of the settings panel. Select a line with of 8 pt, and

click Apply to see the change.

5. Make sure that Auto line styles is selected, then select a

different line color for one of your simulation cases. As you hit

Apply, this color is assigned to that simulation case and will

also be used in later plots.




6. Deselect Auto line styles and then change the color of one of

the simulation cases. Click Apply. The corresponding line

changes color in the active function window, but the simulation

case still has the same color on its settings panel.

7. Select the Axis tab of the Settings panel for the function

window, then select the Annotation sub-tab.

8. Use the Annotation font drop-down menu to select another

font size, and click the B button if you want to display the axis

annotation in bold face. Click Apply to see the changes.

9. Select the Legend tab to customize the automatic legend.

Select to use four rows in the legend. Click OK to apply thechange and close the dialog.

Plot window

It is possible to combine several view-ports in one plot window.

Exercise steps1. Open a New plot window.

2. Click the New object in window icon and select Newfunction viewport.

3. Click and drag to insert the new function viewport.

4. Select one of your cases in the Cases pane. Select Oil and Water production rate from the Dynamic results data

folder on the Results pane. Select Field in the Identifier folder.

5. Click the New object in window button again, but this

time select New map viewport.




6. Click and drag to insert a new map viewport.

7. Select the radio button in front of the Dynamic data sub-

folder of the Views folder on the Results pane.

8. Select to view Oil and Water production rate for all

producers.

9. In addition, select to view a horizon from your upscaled grid on

the Models pane. You should now see a bubble map of the

production in the map window. Use the time player to go to the

time steps of interest.

10. If you want to change the size of the bubbles, right-click the

Dynamic data in the Views folder on the Results pane and

select Settings. Use the sliders under in the Chart scale

section of the Settings panel to set a new bubble radius..

11. Go to a 3D window, and select to display water saturation atthe last time step. Click the Copy bitmap icon. Then click

the Paste bitmap button. The bitmap is stored on the

Input pane.

12. Go back to your plot window and add the bitmap to view by

selecting it from the Input pane.

13. You can drag the bitmap into another position and rescale it

when you are in Select/pick mode .




Summary data in a 3D window - Optional

You can visualize production data with multiple of other data types. The

summary vector is displayed as disc, stack, bar, or sphere and the size

represent the magnitude.Exercise steps

1. Open the 3D window, display the Producers from the Input pane.

2. Go to the settings of Dynamic data under the Views folder in

the Results pane.

3. Select Chart type as Disc, click OK.

4. Under Dynamic results data, select Oil production rate

and Water production rate.

5. Remember to activate the proper Identifier (select the check

box in front of Producers under Identifier folder on the

Results pane).

6. Use the time player to play production data in time.




View data on streamlines - Optional

By rerunning one of your cases using the FrontSim simulator, you can

view the results along streamlines.

Exercise steps1. Open the Define simulation case process, and select the

Basic case from the Edit existing drop-down list.

2. Select Create new case, and name the new case Basic_FS.

3. Select FrontSim from the Simulator drop-down menu.

4. Click Apply to save, and Run to run the case. Then close the

process dialog.

5. Open a 3D window and go to the Input pane, and select to

view the Injectors and the Producers wells. Then, expand

the Streamlines folder under the Upscaled grid in the

Models pane and select to view your case Basic_FS. By

default, the water saturation at the first time step is displayed.

You can use the time player to view the saturation at later time

steps.

6. Expand the Attributes folder and observe the other properties

that can be viewed on streamlines.

7. Select only well I02 from the Startwell filter folder to only

view streamlines starting in well I02.




Lesson 3 (Optional) – History match analysis




Match values are computed for all wells with observed data. In the

expression on the slide:

M is the match value that will be reportedN is the number of points used to compute M, that is the number of

time steps in the simulation or the number of observed data points. You

select which of those to use in the History match analysis process

dialog.

S is the simulated value. S is a vector containing the simulated value

for a specific well at each point in time. Hence, S is a vector of length

N.

O is the observed value, that is, O is a vector containing the observed

value for a specific well at each point in time. O has length N.

s is a normalization parameter that can be used to make sure all the

match values are in the same order of magnitude.




Remember, that since the water cut is the ratio of water to liquid

hydrocarbons produced in a well, it will always have values between

zero and one. Therefore, a well with a large production is notdistinguished from a well with a small production. Consequently, it is

more reliable to use rates when computing the history match data.




History match analysis

Select the Observed data set you

wish to compare your simulation

results to.

Select settings:

• the sample frequency

• zero data filtering

• normalization

The settings apply to all vectors by default.To change the settings for a vector:

1. Select the vector

2. Clear the Use default check box

3. Specify the settings




History match analysis

Sampling

Sampling controls the times at

which comparisons are made.

For infrequent observed data such

as bottom hole pressure, use

Observed frequency to compare

only where observed data is

available.

Remember, the expression for the match value M given in slide 4. The

number N is determined by the sample frequency. If Observedfrequency is chosen, the simulated data is compared to the observed

data only when observed data is available. Consequently, N is the

number of samples of the observed data. The simulated data will be

sampled backwards. That is, at a time where there is observed data this

value will be compared to the first simulated value backwards in time.




If Simulated frequency is selected, the simulated and the observed

data will be compared at all simulation time steps. For each simulated

time, the observed data are sampled forward in time, meaning that the

observed data is treated as a constant from each measured point to the

next. The average observed data value over one simulation time step iscompared to the simulated value.




Zero data filtering should be turned on for the rates that were used to

set the rules in the Development strategy process. If one of those

rates is zero for a well, you would get a perfect match only because the

well is closed for flow.

Note that the normalization parameter s can be used to give one

vector, or a selection of the vectors, more weight than the others in a

combined match.

That is, if a large normalization parameter is used for some of the

vectors, the match value for those vectors will be relatively small

compared to vectors that were assigned a small parameter.

If you select to use Absolute normalization, you must select the size of

the normalization parameter carefully.




History match analysisResults viewing

The history match set is

stored in the Results pane

You can use the data to:

• Compare wells and

vectors for a case

• Compare wells and

vectors between cases

There are several options to view match data:

Function window. Crossplots of two vectors or a vector and a wellcan be displayed in a function window. Also a vector or combination of

vectors can be plotted for several different cases.

Map window. In a map window, the match values can be plotted at

the well position. The data can be viewed together with a surface or a

horizon. Either two cases can be compared at each well, or the match

value for the different wells can be displayed for a single case.




In a map window, you can select to view data in either a qualitative or

in a quantitative mode.

Qualitative mode: The results are grouped into five bins, ranging from

poor to perfect match.

Quantitative mode: The actual match values, M, are displayed.

When viewing match values in the quantitative mode, be aware that

the maximum value depends on the normalization parameter you have

selected. Also, the maximum value may have great variations between

the different vectors.




In the settings panel for the History match set, you can set the

Threshold limits and the Equality number. Updating these values does

not require re-sampling of the data, it only changes the appearance of

the plots.

Threshold: The settings are used to visualize match results in the

qualitative mode. All vectors with a match value lower than Min will

be reported as Match. All vectors with a match value greater than

Max will be reported as Poor. Note that the size of the parameters

Min and Max must be chosen depending on how you select to

normalize the match.

Equality+/-:The number you enter here is used to visualize the

difference between two cases. Vectors with a match value less than

this number will be displayed as being equal.




Match values in Map windowSingle case

A bubble map

shows the match

statistic for one or

more vectors at

each well.

Here, the well

P04 has the worst

oil productionmatch.

In the above illustration, the match values are displayed in a

quantitative mode, which means the actual match values are displayed.

If a qualitative mode was selected, the results would be lumped intofive categories from Match to Poor.




Match values in Map windowCase compare

Select two cases to

compare in theCases pane.

Select vectors and

wells in the Results

pane.

Switch on Case

compare mode

In the above illustration, two cases are compared. The values are

lumped into three categories: Case 1 is displayed as better, equal, or

worse than Case 2.

Function windowHistory match statistics settings

You can select the color for:

• The best match

• The worst match

• The remaining match values

You can select to view:

• A combined match value for allvectors

• A separate match value for

each vector




If you compare several cases in a function window, you can select to

assign the best and the worst match-value a specific color.

If you select to view the match for several vectors simultaneously, you

have two choices. You can either view one combined match value forall the vectors for each case, or you can view a separate match value

for each vector for each case.

Function windowCross plot two vectors

Cross plots can highlight if improving

one match makes another better or

worse.

To make a crossplot:

1. Use the right mouse to select which vector to plot on the

x-axis. Then select a second vector for the y-axis.

2. Select the cases you want to compare in the Cases pane.

A trend to the origin indicates both matches improve together, while a

trend to the ends of the axes indicates improving one match worsensthe other. You can crossplot two wells in a similar way.




Function windowSingle vector versus case number

In the illustration, you can see the match values for a single vector,

water production rate, for all wells in several cases. In this example,

the user has selected to give the best match the color green and theworst match the color red. The remaining matches are in black.




Exercises – History match analysis

In this exercise, you will run the History match analysis process on

the history cases we set up previously. The resulting match-vectors will

be used to explore whether the simulated results reproduce theobserved production data.

Exercise Workflow• Run the History match analysis process

• View results in function and map windows for a single case

• Adjust settings to improve the visualization

Exercise Data

In the following exercise, we will continue with the project we made in

the previous exercises.

Run history match analysis

Exercise steps1. Open the History match analysis process from the

Simulation folder on the Processes pane.

2. Select to Create new match. Make sure that your historicaldata set is selected as the observed data set.

3. Select Water cut, deselect Use default and select AbsoluteNormalization. Enter 1 as the normalization parameter.

4. Select the Bottom hole pressure, and deselect Use default.Then, select Observed frequency.

5. Click OK to compute the math vectors.




View match data in a map window

Exercise steps1. Open a New map window.

2. Select your Aquifer case in the Cases pane.3. Select to view the Base horizon by selecting the check box in

front of it under your Upscaled grid on the Models pane.

4. For only viewing the contour lines, right-click in the Horizons

folder under the Upscaled grid and select Settings.

5. Go to the Solid tab and deselect Show. Click OK to close the

settings.

6. Go to the Results pane and select the new match set. Also

select Bottom hole pressure from the Vector matches

folder. Select all the producers in the Identifier folder.

7. If you do not see the wells, click the View all in viewport

button .

8. Open the settings for History match statistics by right-

clicking the folder and then selecting Settings.

9. Go to the Map window tab and select the radio button

Quantitative.10. Still on the Map window tab, select the check box Enable

bubble plots. Click Apply.

11. Go to the General tab and click to change the range of the

color legend. In the dialog that opens, click Max and Min

to get the range of your pressure match vector. Click




Apply. Notice how well P01 has the poorest match in bottom

hole pressure.

12. Turn off the Bottom hole pressure, and select to view theOil production rate instead.

13. Switch to Qualitative mode in the Map tab of the Settings

panel for the History match statistics, then click Apply.

14. Open the settings for your New match set and enter the

threshold for the match values that should be considered good

and bad. Select Min =0.1 and Max=3. You should now see a

qualitative match of the oil production rates. Notice that well

P04 has a poor match in oil production rate.




View match data in a function window


2. Select all of your cases on the Cases pane.

3. Open the settings dialog for the History match statistics

folder and go to the Function window tab.

4. Select the check boxes Color best match and Color worstmatch, then check the box Combine. Click OK to close the

dialog.




5. Select your New match set, Bottom hole pressure, Oilproduction rate and well P04 from the History matchstatistics folder on the Results pane.

6. You should now see the match values in the function window.

Compare cases in a Map window

Exercise steps1. Open a Map window.

2. Select to view all wells and the Bottom hole pressure from

the History match statistics folder on the Results pane.3. Activate the Case compare button in the function bar. It

should now have an orange background color.

4. Then, select to view both the Aquifer case and the Simple

case.

5. Right-click the New match set folder on the Results pane

and select Settings.

6. On the settings panel, select the Bottom hole pressure, then

set Equality to 0.3.




7. You should now see that the Aquifer case has the best match

for most of the wells.

.




Summary

In this module, you learned how to use the Make developmentstrategy process to set up a simulation case using observed well data

as input. You also learned how to import observed data. Finally, it wasdemonstrated how to use the History match analysis process to

compare simulated results to observed data.



Reservoir Engineering Well Engineering • 263

Module 8 - Well Engineering

Introduction

In this module, we will import well data, digitize a new well in Petrel

using the Well path design process, and complete the well with

completions using the Well completion design process. We will use

various Petrel windows and tools to create, quality check and inspect

the well data.

PrerequisitesBasic knowledge of Petrel is required.

Learning Objectives

In this module, you will learn:

• How to import well data into your Petrel project

• How to design a well path using the Well path design and

the Laterals design processes

• How to use the well completion design process to insertcompletions for your wells

• How to QC wells trajectories and completions.



264 • Well Engineering Reservoir Engineering

Lesson 1 – Import and Design Well Paths

When you import a well header, make sure to select the correct file

format. In the import dialog that appears, notice that there is a capture

of the file you are importing at the bottom. View the data in the file

capture, and fill in the column number for the x and y coordinate and the

depth data into the Columns part of the dialog.

To import well header data:

• Right-click the Wells folder and select Import(on selection)

from the drop-down menu• Select Well heads (ASCII)(*.*) as the file format




Use the Well path/deviation(ASCII) format

to import the well trajectory.

Match file name to

existing well name.

Import well paths

Import well path / deviation file

If the well is not vertical, it is necessary to import the corresponding

deviation file. The deviation file will be attached to the well header

already imported.

Select a well path input file by right-clicking on the Wells folder and

selecting Import (on selection). In the window that opens up, select

the files defining the well paths for one, some, or all of the wells and

select the appropriate format (for example, Well paths/deviations

(ASCII)(*.*)).

Associate each well path with a well

The illustration above shows the window that will open up while

importing. The window displays the well names in the file in the left

column. Use the right column to match the deviation data on file to the

correct well in your project

Link the field types with the file’s columns

As for the well heads file, an Import well deviation window will

open up where you will have to specify which column in the file

corresponds to each of the attributes, such as MD, Inclination and

Azimuth; X, Y and TVD.

A well created by

Create well (vertical well) or

imported into Petrel using

well deviation format is

created by the minimumcurvature interpolation

method. This method is very

different from the advanced

drilling trajectory algorithm

available in Well path

design, both in objective and

mathematics.




To import branching wells, you need to use the Multiple well paths/ deviations file format. Notice that if Well B is branching off from Well

A, then it needs to be named Well A%Well B on the file you are

importing.




Well path design

We will now focus on how to make new well traces in Petrel. The

simplest way to add a new well, is to make a new vertical well. The

Well path design process which is located in the Well engineering folder in the Processes pane allows you to digitize new well traces,

and the Laterals design process makes it easy to add laterals to an

existing well.

Well path design

Make vertical wells

Digitize well paths

Make wells using the Well

path design process




Simple vertical wellTo insert a new vertical well into the project:

1. Decide where in your 3D model you want to locate the new

well.

2. Click the location in a window using the Select/pick mode.

The status bar will display the X and Y surface coordinates.

3. Right-click the Wells folder in the Input pane and choose

New well from the drop-down menu.

4. In the Create new well dialog, enter a name for the well,

select a well symbol and enter the X and Y coordinates. You

can also enter a top measured depth and a bottom measureddepth to specify the depth interval of the well.

A well created by the

Create well is created in the

DxDyTVD domain, and is not

intended to be modified by

the Well path design

process. Therefore these are

the only editable values on

the spreadsheet.




Well path designTrajectory

A well path is generated between the

design points.

The path is a combination of straight and

curved sections; an approximation of how

wells are drilled in the real world.

Petrel algorithm - Advanced Design

Trajectory - will attempt to restrict

curvature to a specified dog leg severity

(DLS).

The well path design process

Well path design lets you create paths for wells either manually by

point-and-click, or automatically using the Create best fit well and

Well optimizer methods.

When designing a well manually, the first step is to start digitizing the

well path and edit the well points into position. This can be done in

several ways, and will be described on the following pages.

Petrel makes well traces through the design point which is a

combination of straight lines and curved sections. Petrel will use a ‘J’

curve between points 1 and 2 (straight section then curve), a straight

section between points 2 and 3 and ‘r’ curves between subsequent

points (curve then straight section).

The Well path design process is creating wells according to the

drilling constraints. Therefore, there is additional data associated with

the well traces exposed in the spreadsheet for each well. The well is

created in the XYZ domain (design points). Consequently, these are the

only values that can be edited in the spreadsheet.

You may want to

change vertical exaggeration

to 2 instead of the default of

5. This should give a betterunderstanding of the well

geometry

The DLS settings

play an important role in

generating the well path

using the ADT algorithm. If

you are not happy with the

generated well path then he

can change these settings, or

edit the well interactively.




Dog leg severity (DLS)

The algorithm will attempt to design a well that passes through all of

the design points with a curvature which is smaller than the “requested

upper” dog leg severity (DLS) set by the user. This is done by using a

series of straight sections and curves of the requested DLS.




Dog leg severity (DLS)

DLS is the deviation from a straightpath in degrees per 30m (100 ft).

The illustration shows the result of using different DLS constraints on

the well path. In the picture at the top, a maximum DLS of 5 was

allowed, while in the bottom picture the highest DLS is set equal to therequested DLS of 3.

The method for computing a trace between the design points, needs

input to decide to what degree the path is allowed to deviate from a

straight line. You need to specify the Dog leg severity (DLS) of the

resulting well trace. The DLS is the deviation from a straight line

measured in degrees per 30 m (or 100 ft ).

Requested - this is the dog leg severity which will be used on the

curved sections of the well path if possible.

Maximum -the maximum dog leg severity which can be used in

the well path. If the requested DLS can not be achieved

because of the positioning of the design points (the points are

too close together and at a too severe angle), then the

algorithm will use the highest DLS required without exceeding

its maximum.




Digitize well path

A) Digitize on a General Intersection

B) Digitize on a filtered property

Display all the data of

interest:

• Property

• Horizons

• Faults

• Seismic etc.

Well design walkthrough

A new well path is digitized in the Well path design process by using

the Add new points button. Later, the digitized points can be edited

and deleted, and additional points can be added.

There are several ways of digitizing the well path, depending on the

available data.

Digitize on a General intersection (GI) - You can create a GI

and position it in the place where you want to digitize the new

path. Any type of data can be displayed on the intersection. It

is possible to perform detailed editing at any time, for instance,

if you do not want your well along a straight line.Digitize on a filtered property - Use the value filter in the

property filter to filter on, for example, high porosity values,

and use the zone filter to view the different zone(s) you want.

Digitize in 3D view and attach the digitized points to the cells

that are left after filtering.

It is also possible to

first create a polygon (that

can consist of severalstraight line segments joined

together), create a vertical

section along the polygon,

display data on the section

and then digitize.




Create a STOIIP map from volume calculation - This map

shows the density for each cell. The STOIIP map can be draped

across the surface representing the top reservoir. The surface

used to digitize the new well should be placed below the top of

the reservoir to make sure that the well trace is always inside

the reservoir.

Digitize well path

1. Activate the Well path design process

1

3. ... or Start new well (Deactivate the old)3

2. Continue digitizing on an existing (active;

bold) well…

2

4. The new well trajectory is stored in the

Proposed wells folder under the main

Wells folder.

Tip: Use these two

options to increase

or decrease point

size.

4




Well typeSimple

Stand

alone

Side

track

You have the possibility to extend the proposed well trajectory to the

surface by selecting one of the Advanced algorithm options:

Simple : The well head is assumed to be vertical above theuppermost design point.

Standalone : The well head, KB and MD need to be provided by

the user.

Side track : User must specify the main well to which Petrel will

connect proposed trajectory.

The Simulation trajectory algorithm is available only for imported wells

from simulation deck. The algorithm joins the design points with

straight lines.




Edit well path

3. Depending on the Move options in function bar (A), you can

move along the Line tangent (B) only, in Vertical plane (C)

only or Free movement

2. Pick a node (yellow) and move by depressing the left

mouse button

2

1. Activate the Select/pick mode from function bar

1

3A

3B 3C

Edit well path

2

2. Active the Z-value selector icon and enter a depth for the

node (press =); moves along tangent vertically

1. Move tangent – select cylinder part of widget (turnsyellow) and move up or down. Pressing CTRL shifts direction

1

3. Move vector arrow (turns yellow). This will not move the

node but changes the curvature (A)

3 3A






5. Under Other settings, select the button Name as part ofheader.

6. In the Name prefix field, enter the characters that precede

the well name in the file you are importing.

7. In the Data format field, enter a N for all columns containing

a number and an S for all columns containing a text string.

8. Click OK to do the import.

9. Add a new sub-folder to the Wells folder and name it

Imported.

10. Move the imported wells P07 and P07%P08 into the Imported

folder that you just added.11. Select to display the new well in a 3D window.




Make a vertical wellExercise steps

1. Right-click the Wells folder and select New well. In the

dialog that opens, give the new well the name P09, and place

it at (x,y)=(4500, 11500) m.

2. Select an appropriate well symbol.

3. Select the check box Specify vertical trace, then enter a

bottom MD of 2900 m.

4. Click OK to make the well.

5. Drag and drop the new well into the Producers folder.

.




Setting up the 3D window

This exercise will walk you through how to display relevant data when

digitizing wells, such as oil saturation at the end of history. Also, it is

useful to display the other wells and the faults so you can see theproximity and avoid hitting them when designing the well.

Exercise steps1. Open a 3D window.

2. Go to the Cases pane and select the Aquifer case.

3. On the Results pane, expand the Dynamic folder under

Simulation grid results, and select to visualize Oilsaturation (SOIL).

4. Display the last time step 2009-02-01, using time player at the

bottom.

5. Right-click the Oil saturation (SOIL) property and selectCreate 1D filter.

6. Select to filter out all values below 50% of oil saturation. Click

Apply.

Be aware of vertical

exaggeration, which bydefault is set to 5. You may

want to change Z-scale to 2

from Petrel Tool bar.




7. Expand the Filter folder on the Input pane. Then, expand the

User sub-folder in which your new filter is stored. Select the

check box in front of it to turn it on or off.

8. Next, click once on the Define simulation case in the

Simulation folder in the Processes pane making it the active

process. This enables the property function toolbar to the right

of the 3D window which we will use.

9. Use the Display the cells with same K button and the

property player buttons to move through the grid in K layers. Inthis way, when you digitize on the grid, you can move through

the reservoir. You can also use the I- and J-direction filters

10. Turn on all existing wells from the Input pane, to avoid

collisions.

This is one way out of many to set up the 3D window ready for

digitizing new well trajectories.

Exercise steps

1. Alternatively, you can use a General intersection as a target

when digitizing the well trajectory in combination with the

saturation property.

2. Go to the Input pane and turn off the User filter for saturation

you have made in the previous exercise Oil saturation (SOIL)1 - Aquifer. Deselect filtering along K-direction as well.

3. Insert a new General intersection by right-clicking the

Intersection folder located in the Models pane under

Upscaled grid. Next, select Insert general intersection

4. Use the Manipulate plane button and the general

intersection player toolbar to move the general intersection

into the location you want to digitize the well.

If you do not have anyproperties to move along,

you may also use a surface

or horizon. Shift the surface

up and down a short interval

using the Operation tab in

the settings for the surface.

Then you can digitize on that

surface to trace the well.




5. When the general intersection is in the position you want, turn

off the Oil saturation (SOIL) property from Simulation gridresults in the Results pane.

6. Toggle on Visualization on plane and then select todisplay a property on the plane, for example, Oil saturation(SOIL) property. The property will now be displayed only on

the intersection.

Open the settings for

the General intersection

plane and set the

transparency very high(90%). Also, from the

function toolbar, select to

Make the point size bigger

so that the well points are

more easily seen.

From the General

intersection player toolbar,

use either the Clip in frontof plane or the Clip behind

plane buttons

to filter out

the cells that covers the

plane.




Well path design

Best practice: Now that the 3D window has been set up to start

digitizing a well path, be cautious. Start off simple and only add more

complexity if it is necessary. Using the digitizer and the widgetfunctionality in Petrel is tempting, but you can easily compromise a well

with a well point that is off.

Exercise steps1. Activate the Well path design process found in the Well

engineering folder on the Processes pane by clicking it

once. This enables the well path design function toolbar that

we will be using.

2. Use the Add new points button in the well path design

function toolbar and start to digitize (click) on the generalintersection plane.




3. To move a well point interactively in the 3D window, use the

Select/pick mode and click on the well point. The well

point turns into a widget that can be moved around. Petrel will

observe the dog leg severity constraints at all times and giveyou a warning if it is exceeded.

The new well will automatically be named Proposed 1 and will be

saved in a new Proposed wells folder under the Wells folder in theInput pane. Right-click on the well and open its settings. Now, you can

define if the well should be a simple well, a standalone well, or a side

track well that tie into one of the existing wells in the project.

4. For our project, we will state that the well is a standalone. We

need to specify a well header location and a kick-off measured

depth. Enter some reasonable values that will not break the

dog leg severity for the well.

It is often easier to

delete a well point, or the

entire well, and start the

well design again, than to

spend time adjusting and

fixing.

To resize, select or

move the well design points

you will have to either turn

off the general intersection

plane or move the plane

slightly.




5. Remember to change the well symbol for the well, and torename the well into something in accordance with the other

wells (P10). The well will be stored in the Proposed wells

folder.




Reference project tool

This exercise will show you how to use the Reference project tool,which is useful when sharing data with others.

Exercise steps1. Go to the File menu and select the Reference project tool.

.

2. Click the Open project button in the Backgroundproject part of the dialog that opens.

3. In the file browser that opens, select the RE_Reference_2010.pet file, then click Open.

4. Expand the Wells folder for this project and select the check

box in front of the P08 well.

5. Click the left arrow to copy the well into your project.

6. Close the Reference project tool, and save your project.

7. Display the well you just copied.




Lesson 2(Optional) – Automatic well placement

This lesson shows an automatic way of creating wells using the Wellpath design process :

Best fit method

This method will place the well in the

geological body defined by the user.

1. Open Well path design.

2. Select method.

Create best fit well

The Best fit well method will place a well in the discrete 3D property

defined by the user.

The well spacing, length, and orientation are controlled by the property

that is used as input.




Best fit method

1. Define the target

area for the new well.

3. Select wellhead or

attach to an existing

well.

In the process

settings, you can turn

on the active filter to

be applied together

with the target body.

2. Drop it into the

process.

3. Give the new well a

name.

Best fit methodAdvanced well placement considerations

Click Make run before you close

the dialog.

a) Multilaterals

b) Limiting surfaces as constrain

c) Collision detection

Shifting offset




The algorithm will place a well through the target body, honoring the

constraint given by the user. The topology of the selected target area

(body) can lead to multilateral solution. On the process dialog, you can

allow for laterals and also limit their lengths.

You can select to constrain the well(s) target points between an upper

and a lower surface. Notice that you cannot use a horizon from the 3D

grid, only surfaces from the Input pane are accepted as input. If the

same surface is inserted for both Upper and Lower, Petrel will shift

the well target points to that surface. Alternatively, you can enter the

maximum and the minimum depth where you want the well path to be

placed in between.

It is possible to shift the wells in the X and Y direction relative to the

input target by entering the desired offset. Notice that by doing so, theresulting wells may not hit the input target.

If you turn on Collision detection , you have to specify a well or a

group of wells that the new well should avoid.

Laterals design

If a collision is

detected, a warning message

will be logged.




The process allows you to create complex multilateral trajectories

based on existing well(s). There are two types of laterals: Fishbone and

Fork laterals.

Laterals design

You need to supply the depth (reference MD) that the first new lateral

should branch off from the mother bore. Either drop in a surface, in

which case the reference MD is calculated as the intersection of the

main well with that surface. Or else, enter the depth (in TVD).




Laterals design

On the Laterals template tab, you can select the laterals type : Fork or

Fishbone. There are several settings for both templates:

Offset MD – This value will define the starting point MD of the

first lateral and is an offset to the reference MD provided on

the general tab.

Spacing – specify the distance (MD) between the starting points

of two consecutive laterals.

Relative azimuth – is the angle between the first target point of

the lateral and the starting point of the main well. In cases

where there are more then one lateral, the first will use the

relative azimuth, the second will use the opposite of therelative azimuth and so on.

Use the Advanced settings if you want to use different settings for

different laterals to the same main well.




Laterals design

You can constrain the well target points (computed by algorithm)

between two surfaces. If the same is used for upper and lower Petrel

will place well target points directly onto that surface.

Exercises – Automatic well placement - optional

Exercise Workflow• Convert simulation results to grid property

• Use grid calculator to define a discrete property

• Well path design - Create best fit well

• Laterals design

In this exercise, we will place a well in the target geobody.

Exercise steps - Make a well target1. Display the Oil saturation (SOIL) property from the Results

pane. Use the Aquifer case from Cases pane. Set the time

player to display the last report step.

2. Expand the Grid filter under Simulation grid results in the

Results pane and deselect all segments except Segment 4.




3. The part of the reservoir that has high oil saturation and only

one producer is now displayed.

4. Right-click Oil saturation (SOIL) and select Convertsimulation results to grid properties. Click OK in the dialog

that opens up.

5. Go to the Models pane. Under the Upscaled grid you will

find the AQUIFER folder (name of the case/ run from which

the property originated).

6. Expand the AQUIFER folder and find the SOIL[0] [Feb01.2009] property. Right-click and select Calculator.

7. In the Calculator window, select to Use filter. The filter that

is applied is the same as the ones applied in the active 3D

window, hence, in this case, we will only compute a property

for Segment 4.

8. Use the Attach new to template drop-down menu to select

the General discrete template.

9. Enter P11_target=, then left-click the SOIL property in the

Select property variable pane to obtain the expression as

shown in the illustration below.




10. Click ENTER in the calculator dialog.

11. The new property is stored in the Properties folder of the

upscaled grid. Display it in the 3D window.

Exercise steps - Create best fit wells1. Open the Well path design process from the Processes

pane.

2. Select method the Create best fit well.3. Drop the new P11_target property into the process window

using the blue arrow.

4. To specify the well head location, there is a pre-made Wellhead P11 point set stored in the Input pane. Drop it in to

the process dialog.

5. Change the maximum length of the new well to bee 4000 m.

6. Leave the other settings default.




7. Click Make run. Find the new Optimized wells folder in the

Input pane and visualize the new wells in your 3D window.

Exercise steps – Laterals design

In this exercise, we will make a multilateral well using the Lateralsdesign process. We will use the horizontal well we digitized in the 3D

window as the input main well. We will add laterals using the Fork

type. .

Exercise steps

1. Display well P10 from the Input pane.

2. Open the Laterals design process from the Processes pane.

3. On the General, tab drop in well P10 as a main well. As

Reference MD, enter a positive number. This is the point (in

total vertical depth) where the first lateral branches off P10.

Leave the DLS settings default.

4. On the Laterals template tab, select Laterals type: Fork.Set the Number of laterals to 2 and enter Laterals length :

3000 m.

The reference MD is

the MD value of the input

well that corresponds to the

TVD given as input to the

process. You can left-click

the main well in a 3D

window at which point

where you want the first

lateral to branch off. The

depth value is then reported

in the status bar.




5. Click OK. The new Laterals folder is added to the Wells

folder in the Input pane. Display the new laterals together

with P10.

Lesson 3 – Results, reports and quality checking

You can adjust

different parameters

including DLS to obtain a

suitable laterals.




Well manager

Well manager is a toolthat displays and

allows to edit well data

in a spreadsheet

Well attributes:

• Default attributes

• User attributes

• Check shots

• Well log

• Well completions

The Well manager gives you an overview of all wells in your project. It

allows you to sort and filter on well names.




The well paths can be viewed and edited in a spreadsheet. To accessthe spreadsheet, right-click the well and select Spreadsheet from the

drop-down menu.




Intersection with HorizonsReport

From the Settings dialog of a well, you can select to create a well

report that can be handed over to the driller. You can either create a

report that tells you all the exits and entries of every zone, or you could

enter the spreadsheet for the well and get a listing of the well points,

with different types of attributes.




Intersection with HorizonsMake well tops

Also on the Settings dialog for the wells, you can select to add

synthetic well tops to the active well tops folder at the positions where

your new wells intersects the horizons of your 3D grid. Those can be

useful later when placing completion items.




There are many options in Petrel to quality check and report the

resulting well path. Both the dog leg severity and the error propagation

cone can be displayed along the well path. It is also possible to make

synthetic logs from grid properties and to view properties on a vertical

well section along the well path. The designed wells can be reviewed

and edited in a spreadsheet.




Display the Dog leg severity

Click the button to display the DLS.

Synthetic logs

1. Open the Make logs tab in the settings for

the new well and select a property .

Click the Make logs button.

1

2

3. Open the Style settings for the property

from the Global well log, and select the

Draw log as 3D pipe option.

3

2. Click the Make logs button.




Synthetic log curves - can be created from the properties in the

active 3D grid or from the zones in the 3D grid. Synthetic logs can be

displayed in 2D or in 3D as a cylinder along the well path where the

thickness of the cylinder represents the value of the log.

To quality check a new well, you can create a vertical well intersection

and display different types of data on it. Also, it is possible to create

synthetic logs along the well path, based on input from the 3D grid. This

could be synthetic property logs (Phi, Perm, Sw, etc) or zone logs. The

synthetic logs can be displayed in the well section window like any

other type of log.

Vertical well intersection – right-click on the new well to insert

a vertical well intersection. The blue button allows you to displaydata on the intersection. The data available for display will show a

blue check box. Examples are seismic, properties, horizons, faults,

and polygons.

Vertical well intersection

2B

2. Use the “blue” button (A)

to display on the plane (B)

1. Right-click the well and select

Create vertical wellintersection.

12A




Exercises – Results, reports and quality checking

In this exercise, we will quality check and report resulting well

trajectories.

Exercise Workflow• Well manager

• Well tops and well report

Well manager and saved searches

The Well manager gives an overview of all wells with their attributes,

well logs and completion items. It also allows you to edit and change

the well data.

Exercise steps1. Right-click on the Wells folder in the Input pane and select

Well manager from the drop-down menu. The well manager

window opens.

You can view the

completion items in the 3D

window. Click in the Globalcompletions folder in the

Input pane to view the

completions for the wells.




2. Hover the mouse pointer over the icons at the top toolbar to

get a tool tip for what functionality they provide. Try a few of

them. Warning: .

3. Click on the Show button to get a drop-downmenu with attributes that you can view. Deselect the default

attributes and select to show Well completions.

4. Next to the Show button is a Filter button . This filters

the Well manager based on any saved searches defined in

your project. See the tip for more information.

5. Show the default attributes again in the well manager, and

click on the Edit points button at the bottom

of the well manager window. Select to edit the total depth TD

(MD), and notice that the column now has a white background

and the values can now be edited.

Well tops and well report

Petrel has all the information required to make a detailed well report

and well tops for our new well.

Exercise steps1. Drag-and-drop well P08 into the Imported folder.

2. Open the settings for the well P08 and go to the Report tab3. Select the options Make well report and Iconize points as

Horizon in active well tops.

4. Make sure the upscaled grid is active, then click the Insertactive 3D grid (in Petrel explorer) button.

5. Click the Run button to generate the report and to make well

tops where the new well penetrates one of the horizons in the

grid.

Do not delete any

wells from your project,

there is no undo! For some

functions, you need to selecta well first (click on the row

number in front of the well

names)

Saved searches let

you display and access wells

based on specific search

criteria. This helps organizing

well data into place holders

without the need for

duplication. Several types of

search criteria can be

applied. Each search can be

used in isolation or in

combination with other

searches.




6. A well report will open in a spreadsheet, and well tops have

been added to the Well tops folder on the Input pane. We

will use this information when we insert completion items.




Lesson 5 – Well completion design

Well completion design

The Well completion design process allows you to create or editwell completion objects for the wells in your project. All completions

have their own settings panel that contain the physical properties of the

completion and the date at which the completion is introduced to

Petrel.

Most of the completion components can be utilized with both ECLIPSE

and FrontSim for simulation.

• Casing - The well is closed for the depth interval of the

casing.

• Liner - The well is closed for the depth interval of the liner.

• Perforation - The well is open to flow for the depth interval of

the perforation.

• Squeeze - The well is closed to flow.

• Stimulation - The transmissibility factor for the connection

between the well bore and the cells it penetrates is altered

according to the skin value the user selects.




• Plug - The well is closed at the position of the plug and

downwards.

• Well test - The well test completion items can all be used

with the standard well model.

• Hydraulic fracture-The well connection factor is altered

based on the settings of the hydraulic fracture.

Define well segmentation

There are two ways of computing the inflow to wells with ECLIPSE;

namely the standard and multi-segment well model. The multi-

segment well model is a special extension to ECLIPSE.

The following items are exported to ECLIPSE only if they are used with

multi-segmented wells settings - Inflow control devices (ICDs), Flowcontrol valves (FCVs), Gas lift valve, Gauges, and Pumps. The

Heater can only be used with ECLIPSE 300.

The standard well models treat the entire well bore as a single entity,

with constant or averaged fluid properties throughout the well. Such

models neglect pressure drops due to friction and inter-phase slip. This




is a reasonable approximation for vertical wells producing from only

one zone. However, in a horizontal well, friction is very important. When

you have one zone producing gas and another producing oil, the

difference in fluid properties (density and viscosity) is important.

The multi-segmented well model in Petrel and ECLIPSE divides the

entire well bore into segments, similar to how a reservoir is divided into

cells when making the grid. Petrel gives each well segment the physical

properties of the casing or tubing that it contains, allowing ECLIPSE to

accurately model the fluid physics throughout the well bore.

The Petrel Define well segmentation process allows you control of

the length of the segments, what angles they cross, and how the

perforated zones connect to them.

Multi-segmented wells is not within the scope of this class.

VFP (vertical flow

performance) tables give the

BHP as a function of the flow

rate, the THP, the water and

gas fractions.

VFP tables cannot be made

in Petrel, but they can be

imported into the Input pane

and used in the Define wellsegmentation process.

FrontSim does not

support the segregated or

multi-segmented well

models. Multi-lateral or

horizontal wells, or wells

with large amounts of cross

flow, are likely to give

different results from

FrontSim than from ECLIPSE100 or ECLIPSE 300. FrontSim

does have a simpler well

bore friction model for use

with horizontal wells, but

Petrel does not generate

data for this option.




Completion itemsInput pane

Completions appear on the Input

pane in a folder for each well

Edit completion data:

• in the Well section window

• from the Completions manager

• on the Settings panel

• using the Operations tab on the

process dialog

Insert a completion item

Left-click in the Completions

track panel to insert a new

perforation.

Enter a date for the perforation.

Click the Add/edit a

perforation icon from the

function bar.




To insert a new completion item, select one of the icons in the Function

bar (Perforation, Casing, Liner...), and left-click in the Completions track of the well section window. You are prompted with a dialog in

which you need to specify the start date for the new item. Once you

have entered a date and closed the dialog box, the new item is added.

The completion items can be edited in the well section window. To do

so, hover the mouse pointer over a completion item.

• When the pointer looks like a hand, you can drag the item up

or down

• When the pointer looks like a double arrow you can stretch orsqueeze the item

You can also zoom and squeeze the well section display. To do so, hover

the cursor above the depth panel. When the cursor looks like a hand,

you can pane the view. When it looks like a double arrow, you can zoom

or squeeze.




Flow path display

Activate the Flow path

display icon to display the

flow.

If the well flows in both the

tubing and the annulus, it will

be modelled as two wells

when exported for simulation.

By clicking the Toggle flow path display button in the function bar,

you can turn on a flow path display.

Completions manager Completions

You can edit completion items from

the Completions manager .




You can view and edit completion items in a tabular view. To do so,

either right-click the Global completions folder and select

Completions manager, or click the Open completions manager button in the Well completion design process dialog. To sort the

data, simply left-click one of the column headings. To reverse the order,

click once more.

To organize the completions data in this tabular view, you have several

options. You can grab a column header and drag it into the position you

like. Alternatively, you can grab a column header into the dark grey area

to group data by that column. Use the Columns drop-down menu to

select which columns to display.




Completions manager Equipment tab

Use this tab to define equipment.

The equipment defined here can be used by

one or more completion items.

On the Equipment tab, you can define the equipment settings that can

be used by several completion items in the project. For each equipment

type, you must assign a name, outer diameter (OD), inner diameter (ID),inner roughness (IR), and outer roughness (OR). By clicking the

Columns tab, you can add additional columns to specify more settings,

such as drift diameter.




You can also edit the Completion data by opening the settings panel.

You can do so by either right-clicking the completion item in the Input pane, or by right-clicking it in the well section window and then

selecting Settings from the drop-down menu.

On the settings panel for Casings, Tubings, Pumps, Chokes, Gas lift

valves, and Inflow valves, you can select which equipment setting you

want to assign.




SettingsPerforations

Give a depth

directly or relative

to a well

Give a start date

The connected

cells within the

perforation will

be reported assingle entry

Depth. If you want to place a completion item at the depth of a well

top, you must put the Well top into the Depth field and then enter the

number 0 into the box to the left of the drop field. This is because the

depth entered here is the offset to the well top.

Diameter. The diameter you enter here is in inches.




Depth intervalPlace completions relative to well tops

Remember, for a designed well, you can make artificial well tops at the

position where the well penetrates one of the horizons in the 3D grid.

This is further explained in the “Well path design” lesson.




Event shiftingGlobal completion items

Allows you to give a defaultdirection of event shifting for

each completion type.




Open hole default valuesGlobal completion settings

The default diameter for an open

hole well is 7.5 inches.

Change the number, or use a

Calliper log to give a new default

value.

Well completion designOperations

You can use the Operations tab to

modify and make completion items.




You can use the Operations tab on the Well completions design

process dialog to edit existing items or to add new completions.

One way to modify existing items is by changing the radius. New items

can be added either for the whole well, or according to a well log.

Discrete well logs with the correct template must be used as input for

Petrel to understand which intervals to complete with which equipment.




Event data can be imported from file. Select between the formats Wellevent data to import perforations, stimulations and work-overs, and

Well tubing data to import casings and tubings. You can also import

completion logs and then use the Operations tab on the Wellcompletion design process dialog to convert them into completion

items.




Notice that if you are only importing perforations, you should select the

check box Add casing to all wells with events. Otherwise, you will

add perforation to a well which is open hole by default, and it will then

be treated as open hole.




The previous slide shows the format of an events file with information

on which data is required. For instance, if the well has been perforated,

the event file should contain the top and bottom depth of the

perforation. Petrel will translate the depth of events into the I, J, and K

cell location, and the simulator will calculate the transmissibility

between the well and the cell.

Completion itemsTime player

Use the Time player buttons to

see the completions change

through time.

Exercises – Well completion design

In this exercise, we will complete the well we imported earlier with a

casing and a perforation. We will use the Well completion designprocess in Petrel. We will also import well completion items.

Exercise Workflow• Use the completions manager to define new equipment

• Set up a well section window• Insert casing

• Edit casing

• Insert perforation




Exercise Data

In this exercise, you will continue the project you have been working on

in the previous modules and exercises.

Exercise steps - Define equipment1. Open the Completions manager dialog. You can access the

Completions manager by right-clicking on the Globalcompletions folder and selecting it from drop-down menu.

2. In the dialog that opens, go to the Equipment tab.

3. Click the Add a new row button , then select Casing and

enter 1 as the number of equipment to be created.

4. Give the casing the name New equipment. Then, specify anouter diameter (OD) of 6.0 inches and an inner diameter (ID) of

5.5 inches.




5. Click Close to save the settings and to close the dialog.

Exercise steps – Insert casing1. Insert a new well section window with the Window > New

well section window command.

2. Accept to create the new Well section template 2.

3. Now you see an empty well section window. Select the check

box in front of well P08 in the Input pane, to display it in the

window. This is the well we imported using the Referenceproject tool. We will use the well section window and the

Well completion design process to create completion items

for P08.4. At the top of the well section window, select to show the

depth track in measured depth (MD) and not in sub-sea true

vertical depth (SSTVD).




5. Go to the Input pane and then expand the Globalcompletions sub-folder located under the Wells folder.

Select to view Casing and Perforation.

6. Next, select the check box in front the Well tops folder to

display the well tops.

7. Activate the Well completion design process in the Wellengineering folder on the Processes pane by clicking it

once. The function toolbar appears with icons (tools) relevant

to the completion design process.

Click the Add/edit casing icon and click inside the Completions track for well P08, Petrel will prompt you for a start date. Enter

2007-01-01.




Exercise steps – Edit casing1. Hover the mouse pointer over the casing and see that it

changes shape into a double arrow when you cross the base of

the casing.

2. You can now click and drag the casing base up and down in

the well section window.

3. Right-click inside the casing in the completion track and select

Settings from the drop down menu. This opens the settings

window for the casing.4. In the settings window, go to the Properties tab.

5. Use the Equipment name drop-down menu to assign the

New equipment to this well.

6. Select well P08 in the Input pane and drop it into the Bot.MD(m) field of the Properties tab. Then, type 0 in the field to

the left to case the well all the way to the bottom. Click OKand observe how the casing is extended all the way to the

bottom of the well.

Exercise steps – Insert perforation1. From the well section window function toolbar, click the Add/

edit a perforation button . We will now insert a

perforation that runs from the top of the reservoir to the

bottom of the well.

2. Click in the well section track somewhere below the well top




representing the top of the reservoir. Petrel will ask for the

start date for the perforation – type in 2007-01-01 – and click

OK.

3. Display porosity from the upscaled grid along with the

completion track. Drag the perforation to a depth with good

porosity. You can also extend the perforation using the

up-and-down cursor when hovering over the perforation at the

very edge (top or bottom).

4. We will place the perforation relative to the nearest well top.

Open up the Completions folder for the well P08 in the Input pane, right-click Perforation and select Place completionsrelative nearest top from the drop-down menu.

5. The perforation changes color to indicate that it is placed

relative to the depth of the well top.

6. Right-click the perforation and open the settings. Go to the

Depth / date tab and notice the top and bottom of the

perforation interval has been set relative to the nearest welltop.

7. In the Settings window, set the top interval depth to 0 to

place the perforation exactly at the well top position. Click OK.

Observe the change in the well section window.




8. Leave the well section window open.

Import well completion events

The Global completions folder contains all of the completion items

that exist for at least one of the wells, and is used as a filter when youare working with completions in a well section window, or to quickly

see the types of completions that exist in the project.

Exercise steps1. Right-click on the Global completions folder and select

Import (on selection). Set the file format to import to Well

event data (Ascii) (*.ev).

2. In the Import file dialog, select the file Dataset >ImportData > Well_engineering > ImportWells.ev. This is

the well event data file for the P07 and the P07%P08 branch.

Click Open.

3. In the Import event data window, check that the Flow namein file are set to match the Petrel well traces.




4. Go to the Import settings tab, and enable the options Add toexisting events and Add casing to all wells with events.

Now, the import will not overwrite any existing events and thewell will get a casing completion.

5. Select the Custom date format radio button, and specify the

date format that you find in the file you are importing.

6. Inspect the third tab, Unknown data, to verify that there is no

unknown data in the input file. Click OK to import the well

completions for P07 and P07%P08.




The completion items are added to the wells in a sub folder named

Completions. Expand this folder to see which completions exist for the

well.

Exercise steps - Examine the imported data:

You should now quality check that Petrel has imported the wellcompletions correctly. We will do this in a well section window.

1. In the active well section window, select to view the wells P07

and P07%P08 from the Input pane, deselect well P08.

2. Expand the Completions folder for both wells to see all of the

completion items that were imported.

3. Select to view the completion items by selecting the check box

in front of the Global completions folder.

4. Go to the Windows pane and expand the folder for the Well

section window. Open the settings for the Well sectionwindow and under the Definition tab, set the Domain to

measured depth (MD).Click Apply.5. Select to view porosity together with the completions items to

check that the perforations are in good porosity zones.

At the bottom of the

Petrel user interface there is

a Time player toolbar. Click

the First time step button to

go to the first date.

Step forward in time to see

when each of the completion

items are added.

You can view the

completion items in the 3D

window. Click on the Global

completions folder in theInput pane to view the

completions for the wells.




Make completions using the Operations tab

Exercise steps1. Right-click the well P09, and select Import(on selection...).

2. Select to import a file of type Well logs (ASCII) .3. Select to import the file Dataset>ImportData>WEll_

Engineering>P09perforation.txt.

4. In the import dialog that opens, make sure to match the

column numbers correctly, then click OK.

5. Go to the Global well logs folder and rename the new log to

Perf.6. Open a well section window, accept to create a new well

section template 3.

7. From the Input pane, expand the Global completions folder

select Casing and Perforation. From the Global well logs select to view Perf.




8. Select to display well P09. You will see the Perf log that you

just imported. Go to the Models pane and select to view

porosity from the upscaled grid.

9. Open the Well completion design process, select the

operation Create simple completions.

10. Drop the P09 well into the Wells field.

11. Change the date to 01/01/2012.

12. Select the options Create casing and Whole well.13. Select the option Create perforation and From log. Drop in

the Perf log you imported.

14. Deselect the options Create liner and Create completionstring.

15. Click Apply to create the completions. Observe the new

completion items in the well section window.







Summary

In this section you learned how to add and import wells to the project.

You first inserted a simple, vertical well, then looked into the process of

digitizing well traces. Finally you learned how to place well into targetsgiven as a discrete grid property automatically. Once the wells are in

place in the project, they need to be completed. You learned how to use

Petrel to add completions to the simulation case. We also looked into

how to edit and manage different completion items both using the Well

section window and the Completions manager.



Reservoir Engineering Prediction Strategies • 335

Module 9 - Predictionstrategies

Introduction

In this module, how to make prediction development strategies will be

covered. It is also demonstrated how to use the Keyword editor to

include features of ECLIPSE that are not yet available through the Petrel

user interface.

Prerequisites

Basic knowledge of Petrel is required.

Learning Objectives

In this module you will learn how to:

• Use the development strategy process

• Insert and modify rules to an existing development strategy

• Make a prediction strategy• Use restart runs to continue a simulation

• Use the Keyword editor to modify cases



336 • Prediction Strategies Reservoir Engineering

Lesson 1 - Prediction development strategy

In this lesson, you will make a prediction development strategy.

Furthermore, you will define a simulation case, using the end results

after the history case, as your starting conditions.

History-Prediction

Prediction:• Used to predict future

behavior

• Gives the rates or

pressures that the wells

should be operated at

forward in time

History:• Done to validate the

model against history

• Use observed rates as

well control data

• Use historic events;dates for perforations

Make a strategy

Use the toolbar to:

Add times

Add wells

Add rules




Default strategies

The Use presets drop-down menu offers four template strategies.

Note that these are intended as starting points for creating a strategy,

and in most cases they require further editing in order to work.• History strategy: Utilizes the first observed data set that is

listed in the Global observed data folder. All wells in the

project are added to the strategy. In many cases, no further

editing is required to make a strategy for reproducing reservoir

volume rates for all wells with observed data.

• Empty prediction strategy: This will give you a blank

strategy, the same as when the process is opened for the first

time.

• Prediction depletion strategy: This sets up a field for

production with no injection. All wells are added to thestrategy and placed under production group control. You must

set field group production target, and start and end dates. It is

recommended to set the minimum bottom hole pressure, and

optionally, the maximum rate limits.

• Prediction water flood strategy: This sets up a field for

production with water injection. Group and well rules are

setup for group production control and full voidage

replacement. Petrel cannot detect which wells are producers

and which are injectors. Therefore, you must drag producers to

the PROD folder, and injectors to the INJ folder. In addition,

you must set the field group production target and start and

end dates. It is recommended to set bottom hole pressure

limits, and optionally, maximum rate limits on both producers

and injectors.




Add times

Add times if you want to

specify different settings

for different time periods.

You can add new times to the strategy, and then add new wells or new

rules to existing wells from that time.

Add wells

You add a new well to the project by selecting it on the Input pane and

clicking the blue arrow in the Make development strategy process

dialog. Similarly, you can add a folder of wells.




Add wellsLinked folders

If you drop in a folder

of wells from the Input

pane, changes to that

folder is going to take

effect in the strategy.

Folders of wells are used to apply the same rule to numerous wells at a

time. There are two types of folders:

1. Linked folders – are added by dropping a wells folder from

the Input pane into the process dialog. The content issynchronized with the Input pane – you cannot edit those

folders within the Make development strategy process, only

delete the whole folder. This means that if you add a well to

the folder on the Input pane, it will be included the next time

the development strategy is exported to the simulator, without

you having to rerun the process.

2. User folders – are added by clicking on the Add a new userdefined folder button on the tool bar, and wells are added to

the folders by dropping in the well from the Input pane, or by

copy/paste or drag/drop within the strategy tree in the processwindow.

To delete a well or a user folder of wells from the strategy tree, simply

select it in the strategy tree and click the Delete key.

When you add wellsto the strategy tree, their

flow path is analyzed. If the

well cannot flow at all – that

is it is cased but has no

perforations – it will not be

added. If the well flows up

both the tubing and the

annulus, two well flows are

added to the strategy tree.








Sometimes, you need to set a parameter individually for several wells.

For example, when you add a Well pressure production control, you may

want to specify a different pressure for some of the wells.

Start by creating a rule as usual, and drop in a folder containing all thewells into that rule. Enter all of the parameters. These will be the same

for all the wells in the folder. Now right-click the rule and select

Convert to tabular rule from the context menu.

The tabular rule will show up as a folder of rules on the strategy tree.

When you have selected the tabular rule, it will show one column per

well in the rule table, allowing you to set individual values for each

well.

RulesValidation

Rules can be valid, invalid, partially valid, unsupported, or inactive.

• A valid rule has all required parameters set.

• A valid rule (with warning) is valid for all selected simulator

but has at least one parameter set that is not supported for

one of the simulators. Those are shown in blue on the strategy

tree.




• An invalid rule has one or more required parameters missing.

These are shown with a cross overlaid on their icon in the

strategy tree.

• A partially valid rule has all of its required parameters set, but

is not supported by all enabled simulators. These are shown

with an exclamation mark over their icon in the strategy tree.

• Inactive rules are either not supported by any of the enabled

simulators or the user has de-activated the rule by using the

right-click menu. These are shown grayed out in the strategy

tree.

The validation status and the icons are updated when you click Apply

or OK, or for the active rule when you click Validate active rule.

Select the report validation check box to have all validation messages

copied to the Petrel message log once Apply or OK have been clicked.

Note that a valid rule will not necessarily create a valid simulation. For

example, many rules have several optional parameters and the

simulator requires at least one of these to be set, but Petrel does not

enforce this. Future versions of Petrel will enhance the validation logic.

Inactive or invalid

rules will not be written to

the simulation dataset whena case is exported.

Move the mouse over

the rule’s icon in the strategy

tree to see a pop-up with its

validation report.




Group control

• Right-click the Groups folder to

add new group.

• Drag and drop wells between the

groups.

Groups are used to tell the simulator how to control several wells at a

time. Often, a group will correspond to a physical structure in the field,

like a platform or a manifold – but it might as well just be a logical

grouping – for example, all the wells producing from Zone 2.Petrel automatically adds wells to the default (first) group when they

are added to the development strategy. You can then add groups using

the Add new group button, and organize wells into groups by dragging

and dropping between groups.

To rename a group, select the group, right-click it and select Rename.

It is important to distinguish between well folders and groups:

• Well folders can be dropped in Wells parameters of rules.

When exporting to the simulator, Petrel exports the rule to thesimulator for every well in the folder. For example: set each

well in a folder to produce 1,000 bbl/day.

• Groups can be dropped in Groups parameters of rules. Upon

exporting to the simulator, Petrel exports the rule to the

simulator once for the group. The simulator works out how to

apportion the rule to the members of the group. For example,

The group structure

can be changed at a laterdate – for example, to move

a well from the producers

group to the injectors group.

Simply add the new control

date, copy the groups folder

to the new date, and edit the

group structure accordingly.




make the field produce 10,000 bbl/day from 10 wells – but it is

up to the simulator to determine how much each well should

contribute to the field target.

GroupsMembership changing with time

• Add a new time

• Add two groups

• Add a group control rule for both

time intervals

• Assign the rule to one of the

groups in each time interval




Edit and use

• The strategy is stored on the Input pane.• Copy/Paste on the Input pane.

• Drop into the Strategies tab of the

Define simulation case process.

You can copy and paste a development strategy on the Input pane and

then open the copy in the Make development strategy process to

quickly recreate a similar strategy.

Restart runs

F i e l d P r o d u c t i o n

R a t e

History Period Prediction Period

(Base Run)(Restart Run)

Time

Cell

Saturations &

Pressures

recorded

Use the solution at the end of a

history case as start condition

for a prediction run.

Saves time as you do not

recalculate pressure and

saturation for the history period.




Restart runs

1. Right-click on case that

has been run, and select

Insert restart case.

2. In the Define simulation

case, select the restart

case for edit.

Exercises – Prediction strategies

In these exercises, we will create prediction development strategies

using the Make development strategy process in Petrel.

Exercise Workflow• Use a default strategy

• Add a new rule to an existing strategy

• Define a prediction case

• View simulation results

Exercise Data

In the following exercise, we will continue on the project we created in

the previously. Or you can use backup project Mod_8_Completed.pet.

Use a default strategy


2. Select Create new development strategy.

3. Click the Use presets button, and select Prediction waterflood strategy.




4. In the strategy tree of the process window, drag the producers

into the PROD FOLDER and the injectors into the INJ folder.

5. At the top of the left panel, you find the start date. Double-

click it and change the start date to 2009-02-01.

6. Similarly, at the bottom of the left panel, there is a date

subject. Double-click it to edit and select to run the simulation

case for 5 years.

7. Click on the Group rate production control item in the Rulesfolder. Enter a Reservoir volume rate of 150000 m3/d, then

use the drop-down menu to specify this rate as a target.

8. Click on the Group voidage replacement injection rule,

and enter a Voidage replacement fraction of 1.

9. Next, click on the Well rate production control rule. Make

sure that the PROD FOLDER is dropped in as Wells, and that




the control mode is Group control. Leave the remaining fields

blank.

10. Click on the Well pressure production control. Again, the

PROD FOLDER should be dropped in at the Wells field. Select

Limits as Control mode from the drop-down menu. Specify a

Bottom hole pressure limit of 100 bar. Leave the remaining

fields blank.

11. Click on the Well water injection control rule. Check that

the INJ FOLDER is dropped into the Wells field and that

Control mode is set to Group control. Also, enter a Bottomhole pressure limit of 400 bar.

12. Finally, click on the Reporting frequency rule and select to

report every sixth month.

13. Click Apply to save the development strategy.

Add a new rule to an existing strategy

Exercise steps1. If closed, open the Make development strategy process,

and select Edit existing.

2. Select the water flood strategy you made in the previous

exercise from the drop down list.

3. Click the Open ‘Add rules’ dialog button .

4. In the dialog that opens, left-click on the Well water cut rule

located in the Wells folder. Click the Add rule button. Click

Close.

5. In the new water cut rule, drop the PROD FOLDER into the

Wells field.

6. Type in a Water cut limit of 0.9.

7. Select Close well as Water cut action by using the drop-

down menu.




8. Click the Validate active rule button to check the validity of

your new rule.

9. Click OK to save your development strategy and to close down

the process dialog.

Define a prediction case

Exercise steps1. Go to the Cases tab. Right-click the Aquifer case, and select

Insert restart case.

2. Open the Define simulation case process from the

Processes pane.

3. Select Edit existing case, and then select your restart case

from the drop-down menu. Note that the settings under the

Grid, Functions, Strategies tabs were preserved and that

these settings are not editable.

4. Go to the Strategies tab.

5. Add a row to the table by clicking the Append item in the table button .

6. Select the Prediction waterflood strategy 1 on the Inputpane, and drop it into the table by pressing the blue arrow .

7. Select 1st of February 2009 as Restart date.

8. Click Apply to save your case, then click Run to run the

simulation.




View simulation results


2. Go to the Cases pane and select both the aquifer case thatyou used to restart from and your new prediction case.

3. Go to the Results pane and select to view Pressure for the

Field.

4. Use the same function window and deselect to view Pressure

and select Oil production rate.

5. Deselect Filed identifier and select to view the Wells P05 and

P09.6. Notice how P09 starts to produce between 2011 and 2012.

This is the reason of small pressure draw down in the previous

plot.

If you want P09 to

start producing when the

perforations open for thiswell in 2012. Go to Eventshifting under the Settings

for Perforations>Depth/date

tab>select Even

shifting>Specify Date.




Make a strategy with a tabular rule - Optional


2. Select the radio button Create new development strategy.3. Select Empty prediction strategy from the Use presets

drop-down menu.

4. Give the new strategy a name, for instance “Tabular rule”.

5. Double-click on the start date and change it to 2009-02-01.

6. Double-click on the end-date and change it to 2014-02-01.

7. Click on the Report frequency rule, and select a Reportfrequency of 6 months.

8. Insert the Injectors, the Producers, and the Imported folder

of wells from the Input pane.

9. Right-click the Wells folder inside the process dialog, andselect Add new user folder.

10. Name the new folder All producers, then drag and drop theProducers and the Imported folders into it.

11. Right-click on both the Producers and the Imported folder

(you can select both by pressing down CTRL) and select the

Merge with parent folder.

12. Click the Add rules button to open the rules dialog.




13. Select to add a Group voidage replacement injection, a

Well water injection control, a Well rate productioncontrol, and a Well pressure production control rule.

Close the Add rules dialog.

14. Left-click on the Group voidage replacement injection rule

and drop the group Field into the rule and select a Voidagereplacement fraction of 1.

15. Left-click the Well water injection control rule and drop theInjectors folder into the Wells drop-field. Select Groupcontrol as control mode.

16. Left-click on the Well rate production control rule. Drop in the

All producers folder into the Wells drop-field, select

Reservoir rate as the Control mode, then type in a oil rate

of 10000 m3/d.

17. Right-click the new Well rate production control rule in the

Rules folder and select Convert to tabular rule from the

drop-down menu.




18. In the tabular rule, change the Reservoir volume rate for

wells P02, P05, P08, and P09 to 20000 m3/d.

19. Left-click on the Well pressure production control rule, and

then drop in the All producers folder in the Wells field, then

select Limit as the Control mode.

20. Enter a Bottom hole pressure limit of 100 bar.

21. Click OK to save the new strategy.

Exercise steps1. Go to the Cases tab. Right-click the aquifer case , and select

Insert restart case. A new case, Aquifer_RESTART_1,appears on the Cases pane.

2. Open the Define simulation case process and select to edit

the restart case you just created.

3. Go to the Strategies tab.

4. Add a row to the table by clicking the Append item in the table button .

5. On the Strategies tab, drop in your new strategy Tabularrule.

6. Click Apply to save the case, and Run to run it.

7. Open a function window, and examine the results. In particular,

notice the rates of the producers.




Lesson 2 – Keyword editor

Keyword editor

Some functionality is

not yet available from

the Petrel user

interface and mustbe accessed by

manually inserting

keywords.

In some cases,

Petrel generates a

keyword but the

user want to do

manual editing, e.g.,

conversion of

ECLIPSE to Petrel

project.

There are still some ECLIPSE and FRONTSIM functionalities that cannot

be accessed through the Petrel user interface and hence the required

keywords are not exported by Petrel. In such case, it is possible to add

and edit the keyword as user keyword via the Editor.




Keyword editor

Examples are:

• Thermal simulations

• Simulator tuning

• Output additional summary

vectors

As an example, you can use the Keyword editor to report the elapsed

time of a simulation run.

Keyword editor

The Keyword editor is accessed from:• Advanced tab of the Define simulation

case process, or

• Cases pane. Right click a case and

select Editor…




Sort by section:Keywords listed to the right

belong to the

ECLIPSE/FrontSim section

selected to the left

Keyword editor Sort by section

When Sort by section is selected, the keyword editor shows:

• Left: All keywords in the simulation deck sorted by section

• Right: All available keywords. When a section heading is

selected, the list is filtered so that only keywords belonging to

that section are listed.

Keyword editor

Sort by include file

Sort by include files:

the list on the left side

shows the include files

that can be edited

Expand by using the +besides the file name to

list the keywords

contained in the file.

When Sort by include files is selected, the left side of the Keywordeditor shows the include files that can be edited. Double-click a file to

open it in an editor.




Keyword editor Inserting keywords

The list on the right hand

side contains all keywords

for the highlighted section

Keywords can be inserted

or removed using the Insert

and Remove buttons.

To insert a new keyword:

• Highlight the section where you want to insert the keyword

• Select the keyword from the list to the right

• Click Insert• Edit the new keyword in the editor that opens up

• Move the keywords into the correct position in the section byclicking the Up or Down buttons.






Petrel tags keywords and files to indicate how the keyword was

created. The keywords are displayed in red, blue or black:

• Blue: a Petrel generated keyword which is part of a file that

can be edited by the user.• Black: a keyword that has been edited/inserted by the user.

Petrel is not allowed to overwrite it, even if the settings are

changed from the Petrel user interface.

• Red: a file which is generated by Petrel that cannot be edited

by the user. Petrel will overwrite the contents of this file

regardless of whether the keywords contained in the file are

marked as black or blue. In addition, section head keywords

are shown in red.

When Petrel creates a keyword it adds the following comment

“ -- Generated : Petrel ”

This indicates that Petrel will overwrite this file and not preserve

any changes made by the user. If you remove this comment, Petrel

will not do any changes to the keyword it contains even if new

input is given from the Petrel user interface.

“--!!! Generated file. Any edits to this file will be lost on next exportfrom Petrel.”

This indicates that Petrel will overwrite this file and not preserve any

changes made by the user. If you remove this comment, Petrel will not

do any changes to the keyword it contains even if new input is given

from the Petrel user interface.




Keyword editor Preserving keyword edits

To make a Petrel keyword into a

user keyword, blue to black:

• Right-click the keyword and

select User keywordOR,

• Delete the comment line above

the keyword.

Preserving keyword edits




You will notice that if you make a new simulation case by opening an

existing case in the Define simulation case process and selecting

Create new case, then all keywords that were inserted manually are

lost. To make a new case containing all the new keywords, select the

case on the Cases pane and press CTRL and C /CTRL and V to copy/

paste it. The copy can then be opened in the Define simulation case

process for further edits.

Keyword documentation

Right-click any keyword in the

tree and select Documentation.

Right-click on any keyword in the Keyword editor and select

Documentation to open the Eclipse/FrontSim manual for that

keyword.




Import existing simulation case

Import a case - Select file

Right-click in the Cases pane

and select Import (on tree)…

1. Set Files of type to be

ECLIPSE/FrontSim data

and results.

2. Select .DATA, or .EGRID etc.

and Petrel will locate the

other files, if available.

A simulation data file, with or without results, can be loaded to Petrel

in the Cases tab.

Import a case - Selection of files

Petrel will locate all necessary

files, if available. You can also

make your own selection.

The Simulator is auto selected

based on the data file.

Make sure it is correct as it

cannot be changed after import.




Assuming all the files have a common root name and are in the same

directory, Petrel will identify them for loading.

Import a case - Units issues

The units cannot be changed after

import.

You will receive a warning

if the project you import does

not match the unit system of your

current project.

Click on Change if your current

project is empty.

Petrel will, by default, assume that the imported files have the unit

system selected in the project settings. If you attempt to load asimulation case with data from another unit system, Petrel will warn

you and ask whether you want to change the project units to match the

incoming data. If you select to change the unit system, data that is

already in the project will not be converted. Hence, it is only when you

are importing a case into a new, empty project that you should select to

change the unit system. Note that Petrel cannot do unit conversion after

import.

If you click on Continue, then:

• The grid geometry and 3D properties imported into Petrel willbe converted into project units

• Summary line graphs imported into Petrel will be displayed in

project units

• The keyword data will remain in the original units




Customize units

If you run the ECLIPSE case again from Petrel and load its results, the

results will be converted to project units.

Similarly, if you are creating cases within Petrel, you can customize theunits in the Project > Project Settings > Units to be different in the

simulator to the project units. Working in this mode will cause Petrel to

convert keyword data on export, and results on load, between the

simulator and the project units. You should be careful when you are

working in a mixed unit mode! It is very easy to get confused and make

mistakes.

Import a case – Petrel objects

Well data from the

RESTART files in the

Input pane.

Summary data and 3D

Grid and properties in

the Results pane.

Simulation case added

to the Cases pane.

CAUTION: These

settings only apply on import

and export. Changing the

units in the templates or in

the Project Settings after you

have imported the data have

no effect on the numbers, it

simply changes the display

label.




Import a case - Convert to Petrel case

You can convert the imported

case to a Petrel case. Right-click

the case and select Convert to

Petrel case.

Most items are converted

including:

• Fluid model

• Rock physics functions

• 3D grid properties

The development strategies are

NOT converted.

The SCHEDULE data is not converted to a development strategy in

Petrel. You can still run the case from Petrel by right-clicking on thecase in the Cases pane and select a Simulation run only. The

SCHEDULE data will then be read from the file.




Examples of use of the Keyword editor

Keyword editor Summary vectors

Select the SUMMARY section.

Select the additional vectors you

want, for example connection oil

production for a well.

To report other summary vectors than the ones listed on the Report tab

of the Define simulation case process, you can use the Keywordeditor:

• Select the SUMMARY section in the left part of the Keywordeditor

• Select the vector you want to report in the list on the right side

• Check the syntax of the keyword in the manual if necessary

• Click the Insert button and edit the keyword in the editor that

opens




Keyword editor Tuning the simulator

Insert the TUNING keyword

into the SCHEDULE section.

Default tuning is usually good

enough for ECLIPSE.

Use with caution.

If you need to make changes to the ECLIPSE time stepping or the

convergence criteria, you must use the Keyword editor. In FrontSim

there are several options for setting the tuning parameters for the

simulator from the Advanced tab of the Define simulation case

process.

Exercises –Keyword editor - import a case

These exercises shows you how to use the Keyword editor to access

the ECLIPSE/FrontSim keywords.

Exercise Workflow• Import a simulation case

• Edit the case using the Keyword editor

• Convert to Petrel case

Exercise Data

In this exercise, you will open a new Petrel project and import an

existing case from the folder ImportData>KeywordEditor.




Load a simulation case

Exercise steps1. Open Petrel, or start a new project if Petrel is already open.

2. Go to the Cases pane.3. Right-click and select Import (on tree).4. Ensure Files of type is set to ECLIPSE/FrontSim data and

results (*.*)

5. Navigate to the folder ImportData > KeywordEditor containing

BRILLIG.DATA.

6. Click on BRILLIG.DATA then click Open. This opens the ImportECLIPSE / FrontSim run dialog.

7. As there are no results, the only file to load is the .DATA file.

Ensure the Simulator is set to ECLIPSE 100.

8. At the bottom of the Import ECLIPSE / FrontSim run dialog,

deselect the Automate handling of import settings option.

Click the Advanced button.

9. In the window that opens, select Global coordinate system.

In the Remove cells part of the dialog, deselect to use Flatcells with no volume and pillars with equal z-values.




10. Click OK. You will be prompted with a question asking whether

you want to change the project coordinate system to match the

import data. Click Change. The ECLIPSE file is loaded intoPetrel.

11. Select to use NULL as coordinate system if prompted.

12. Save the project to the folder containing the BRILLIG data.

Edit the case

Exercise steps1. Right-click the BRILLIG case on the Cases pane and select

Editor to open the Keyword editor.

2. Expand the GRID section. Locate the NOGGF keyword. Right-click it and select Documentation to get an explanation of

the keyword and any associated parameters.

3. Close the documentation and remove the keyword from the

case by selecting it and clicking the Remove button.

4. Click on Apply to save the changes.

5. Select Sort by include files in the Keyword editor.

The list of keywords

on the right side is sensitiveto the section selected on

the left. For example, click on

GRID to see only the relevant

keywords on the right hand

side.




6. In the Keyword editor, scroll down the left hand side and

highlight a keyword inside the SCHEDULE file (BRILLIG_SCH.INC).

7. Select the INCLUDE keyword from the right hand side and

insert it in the left hand side by clicking Insert.8. Enter the VFPI.TXT file in the INCLUDE file. The file contains

VFP tables for your wells. Save and close the text file.

9. Click on OK to save the changes and to close the Keywordeditor.


Run the simulation case

Exercise steps1. Right-click on the ECLIPSE 100 case again and select

Simulation run only.2. Browse the Input, Models, and Results panes. Expand the

Simulation grid results folder in the Results pane, locate

your case in the Cases pane and display the simulated

properties in a 3D window (Dynamic folder).

3. Open a function window from the Window menu, expand the

Dynamic results data folder in the Results pane. Ensure

BRILLIG is selected for view on the Cases pane.

4. Review some of the summary data vectors. You may need to

use the View all in viewport icon to see the entire data

range.




Convert to Petrel case

Exercise steps1. Right-click on BRILLIG in the Cases pane and select Convert

to Petrel case.2. A message log will give you information on the keywords that

could not be converted to Petrel objects.

3. Inspect the Input and the Models pane. A fluid model and

rock physics functions has been added to the Input pane, and

a new model containing 3D grid properties is added to the

Models pane.




Summary

How to set up prediction development strategies in Petrel has been

covered in this module. How to add additional rules and organizing the

wells into groups or folders of wells was covered. We have alsocovered the use of the Keyword editor to enable options that are not

yet available inside the graphical user interface in Petrel.





Reservoir Engineering Appendix 1- Advanced Workflows • 375

Appendix 1 - Advanced Workflows

Dual porosity – Dual permeability

Fluids exist in two

interconnected systems.

Reality

Simulator approximation

In a dual porosity reservoir, fluids exist in two interconnected systems:

• The rock matrix, which usually provides the bulk of the

reservoir volume

• The highly permeable rock fractures.

If the matrix blocks are linked only through the fracture system, thiswould conventionally be regarded as a dual porosity single permeability

system, since fluid flow through the reservoir takes place only in the

fracture network with the matrix blocks acting as sources. If there is the

possibility of flow directly between neighboring matrix blocks, this is

normally considered to be a dual porosity dual permeability system.

Dual porosity dual

permeability runs are

computationally more

expensive than dual porosity

single permeability runs.



376 • Appendix 1- Advanced Workflows Reservoir Engineering

To model such systems, Petrel will generate two grids – one

representing the matrix and the other representing the fracture volumes

of the cell. The porosity, permeability, depth (etc) properties of both

grids may be independently defined. A matrix-fracture coupling

transmissibility is constructed automatically to simulate flow between

the two systems due to fluid expansion, gravity drainage, capillary

pressure, etc. In a dual porosity run, the number of layers in the

Z-direction should be doubled. The simulator associates the first half of

the grid with the matrix blocks, and the second half with the fractures.


Create fracture network model using the

Create discrete fracture network

process

Scale up fracture network properties:

porosity, permeability (3 or 6 tensors),

sigma

The Scale up fracture network process converts the discrete fracture

network (with its defined properties) into the properties that are

essential for running a dual porosity, or dual permeability simulation, in

ECLIPSE or any other simulator. These are fracture porosity, fracturepermeability (3 or 6 tensors) and sigma factor (the connectivity between

the fractures and the matrix).





Add fracture system to simulation:

2. Drop in fracture properties and

the dual porosity matrix-fracture

coupling transmissibility

1. Select simulation type

3. Add relative permeability curves for the

Fracture system

4. Set Advanced dual porosity settings (no

DP multiplier and Gravity drainage)

1

2

3

4

Sector modeling

Sector modeling allows you to simulate a portion of a reservoir - the

region of interest - using boundary conditions extracted from a

(previously run) full field model. This is useful when planning an infill

drill well, designing a complex completion or matching a well’s

performance to observed behavior. The sector model simulation will run

much faster than the full field model.

There are two distinct workflows for sector modeling. The main

difference is whether the regions used to identify the region of interest

are defined before or after the full field run is performed.

Regions defined before running the full field model allow the boundary

conditions to be captured by the simulator at every time step during the

full field run, and results in a more accurate sector model simulation.




To define a region, you can use the Geometrical modeling tool. In this

example, a region around well P03 is created.




The previous illustration shows where to insert the region of interest in

the Define simulation case process dialog in order to capture the

boundary conditions for a well region during a full field run.

Sector modelingInsert a sector model

Once the full field model has run,

the boundary condition for the

region is stored on the Models

pane.

Right-click the full field case in the

Cases pane and select Insert

sector model.

Once the simulation has run and the results are loaded, a new folder is

added to the Models pane. This folder is named Sector modeling and

contains the boundary condition that was captured at the boundary of

the region that was used as input.

To insert a sector model, right-click on the full field model in the Cases

pane and select Insert sector model. A new case is then added to the

Cases pane. You can open the case in the Define simulation case

process to supply the boundary condition.




Sector modelingRun a sector model

Open the Sector modeling in the

Define simulation case model,

and drop in the boundary

condition captured during the fullfield run.

Hysteresis

Hysteresis: When the curve used to determine the rock properties is a function of the

history of the rock and a function of the direction of the change in the saturation.

Hysteresis enables you to specify different saturation functions for

drainage (decreasing wetting phase saturation) and imbibition

(increasing wetting phase saturation) processes for the simulation case.

A typical pair of relative permeability curves for a non-wetting phase is

shown in the figure. The curve 1 to 2 represents the user supplied




drainage relative permeability table, and the curve 2 to 3 represents the

user supplied imbibition relative permeability table. (Note that non-

wetting phase saturation increases from right to left in this diagram).

The critical saturation of the imbibition curve (Sncri

) is greater than that

of the drainage curve (Sncrd

). The two curves must meet at the maximum

saturation value (Snmax

).

The primary drainage curve is for a process which starts at the

maximum possible wetting phase saturation (Swmaxd

). If the wetting

phase saturation decreases to (Swmin

), this primary drainage curve is

used. In a similar way, if the initial saturation is (Swmin

), and the wetting

phase saturation increases to (Swmaxi

), the imbibition table data will be

used.

If the drainage or imbibition process is reversed at some point, the dataused does not simply run back over its previous values but runs along a

scanning curve.

Hysteresis

Select drainage relative

permeability curves and imbibitions

relative permeability curves in the

Functions tab.

Drop in saturation functions from

the Input pane.

For cases with the water saturation increasing: Imbibition curves should

be used.

When (in a grid block) the saturation of water increases and then the

saturation of gas increases – Hysteresis should be used.

You supply two saturation function tables for the simulation case.




These provide respectively the primary drainage and pendular

imbibition curves.

Case managementRemote job submission

It is possible to submit jobs

from Petrel to a Linux/Unix

computer.

To do so you must:

• Install support for remote

simulation

• Configure Petrel for remote

job submission

• Define queues in Petrel

Remote job submissionPetrel can run simulations in ECLIPSE and FrontSim either on your local

PC, or on a remote server. In either case, you must have an installation

of ECLIPSE Simulators on your PC, version 2006.1 or newer: this

includes an application called eclrun.exe which is used by Petrel to

submit simulation runs.

If you wish to submit runs to a remote machine, you need to configure

both Petrel and the server.

See the Online Help for more information.



Reservoir Engineering Course Index • 383

Index

Symbols

3D gridskeleton grid, defined, 49

defined, 14

3D viewing, 1231D filters, 124

creating intersection window, 128

how to apply filters, 129

how to make filters using a Histogram window, 131

how to use I, J, and K filters, 131

how to view data on an intersection plane, 133

inserting intersections, 128

multi-value probe, 134

results viewing, 129

ternary property,

user filters, 126

well filters, 126

+/- Sign, 27

A

Active item, 26

Advanced tab

selecting formats, 118

Algorithmsfor discrete properties, 168

in scale up properties, 166

Aquifers, 195. See also Make aquifers;

adding, 203

Averaging (cell count)in scale up properties, 166

Averaging methodsin scale up properties, 167

Averaging (volume-weighted)in scale up properties, 166

BBased on input data, 155

Base surface, 52

Binarygrid data, 118

Bitlock, 40

Black oil models, 67

by manual settings, 72

dead oil, 72

default models, 72

dry gas, 72

gas properties, 73

heavy oil+gas, 72

how to plot, 83

importing a keyword fluid model, 83

importing fluid models, 81

initial conditions, 75

light oil+gas, 72

make contacts, 77

making a table with initial conditions, 76

oil properties, 74

separator conditions, 72

specifying fluid phase, 72

using a spreadsheet to model the variation with depth, 78

Bold Item, 26

Boundary

in pillar gridding, defined, 141

Boundary for the Pillar griddefined, 14

Branching wellsimporting, 266

Bubble plotsfor observed data, development strategies and simulation

data, 234

Bubble point line, 68

Bubble point pressure, 78



384 • Index Reservoir Engineering

CCapillary pressure, 95

Cartesian Dx, Dy, Dz, 183

Cartesian Gradual Dx, Dy, Dz, 183Cartesian Gradual Nx, Ny, Nz, 183

Cartesian Nx, Ny, Nz, 183

Cases pane, 26, 27

defined, 14

Casing, 306

Cell

defined, 14

Cell angles, 157

cell inside-out, 158

Colors

specifying line styles for simulation results, development

strategies and observed data, 227

Comments tab, 34

Compaction

rock compaction function, 89

Completions. See Well completion design

Components tab

adding new, 70

Compositional fluid model, 67making, 70

Conditionsinitial conditions for black oil models, 75

Contact level, 78defined, 14

Contact set, 75

Corey correlations

in make rock physics functions, 92

Corner point griddefined, 14

Correlation library, 66

Create a STOIIP map from volume calculation,

Critical point, 68

DDead oil, 72

Define simulation case, 108

advanced tab, 118selecting grid type, 118

Depthplacing completion items at depth, 315

Development strategies, 208adding a rule to limit the production pressures, 222

averaging data, 216

bubble plots, 234

combining view-ports in one plot window, 238

default strategies, 212

defining a history case, 217

defining and running simulation cases using history

development strategy, 223

exporting simulation results, 231

filtering results tree, 230

history match, 208

history strategies, 209

how to change the line style in function windows, 236

how to create a history strategy, 213

how to import observed data, 217

how to make a history development strategy, 217

how to visualize the observed data, 219

importing observed data, 210

line styles, 227

plotting, 215

plotting data, 226

prediction mode, 209

selecting, 108

viewing observed data in a function window, 212

view the history development strategy data, 221

water cut, 244

Deviation fileimporting, 265

Dew point, 78

Dew point line, 68

Digitizing

fault, 56

well paths, 272



Reservoir Engineering Index • 385

Directional averagingin scale up permeability, 167

Directionsdefined, 14

Discontinuous surface, 52

Dongle, 40

Dry gas, 72

Dual porosity dual permeability systems, 375

E

Eclipse

importing keyword files, 81

remote job submission, 382

Empty prediction strategy

defined, 337

Endwell filter, 236

Equality+/-, 251

Equilibration, 113

Equipment tab

defining settings, 313

Erosional surfaces, 52

Event data

importing perforations, stimulations and work-overs, 320

Explorer panes, 25

FFault

defined, 14

Fault filterdefined, 53

Faultsassigning transmissibility multiplier, 58

excluding in pillar gridding, 146

how to insert into grid, 57

how to make a simulation fault, 61


inserting into grid, 56

Filtersdefined, 14

fault filter, 53

how to make filters using a Histogram window, 131

how to use I, J, and K filters for 3D viewing, 131

how to use value filter, 162

making from function and histogram windows, 126

streamlines, , 235well filters for 3D viewing, 126

zone filter, 53

Flow-based upscalingin scale up permability, 167

Flow pathsturning on display, 311

Fluid models ; See also Make fluid modelassigning separate to regions, 112

compositional model, 70

making, 69

Fluidsspecifying fluids phase in black oil models, 72

Follow base, 54

Follow top, 54

Formats

for exporting grid data from models pane, 118

Fractions, 54

FrontSim

remote job submissions, 382

Function bar, , 28defined, 15

Function windowdefined, 15

G

Gas properties, 73

General intersections

creating intersection window, 128

inserting, 128

viewing data on an intersection plane, 133

General surface, 52

General tab

used in black oil models, 72

Grayed-out area, 28




Gridscreatings grids without faults, 48

how to make a simple grid, 48, 59

Skeleton grid, defined, 49

Grid separate zonesin local grid refinements, 184

HHeavy oil+gas, 72

Help manual. See Online help manual

Histogram windowdefined, 15

History matching, 208crossplotting two vectors, 254

how to compare cases in a map window, 260

how to run history match analysis, 256

how to view match data in a function window, 259

how to view match data in a map window, 257

match values in map window, 252

normalization, 248


sampling, 246

settings, 245

setting threshold and equality, 251

single vector versus case number, 255

statistics settings, 254

viewing data in a function window, 249

viewing data in a map window, 249

zero data filtering, 248

History strategies, 209adding a rule to limit the production pressures, 222

defined, , 337

defining a history case, 217

defining and running simulation cases, 223

editing default rules, 215

how to create, 213

how to import observed data, 217

how to make a history development strategy, 217

how to visualize the observed data, 219

plotting data, 226

viewing the development strategy data, 221

History tab, 34

Horizons. See also Make horizonsbase surface, 52

defined, 15

discontinuous surface, 52

erosional surfaces, 52general surface, 52

inserting into simple grid, 50

make horizons process, 51, 52

types of, 52

Horizontal wells, 308

Hysteresis, 380

I

Icons

used in this manual, 13

Importinga polygon, 190

branching wells, 266

fluid models, 81

rock physics functions, 97

well header, 264

well path deviation, , 276

well path / deviation file, 265

Info tab, 34

Initial conditions tab, 75

Initializing the model

3D initial properties, 116

by equilibration, 113

methods for, 110

model, 108

with fluid and rock physics functions, 120

Input pane, 25, 26defined, 15

Insert horizons, 50

Interface, 41

Intersection

defined, 15

Intersection windowdefined, 15

Irreducible saturations, 94




KKey Pillars, 140

Keyword editor, 355

defined, 15documentation, 362

how to convert to Petrel case, 372

how to edit the simulation case, 370

how to load a simulation case, 369

how to run the simulation case, 371

inserting a new keyword:, 358

preserving keyword edits, 362

setting the tuning parameters for simulator, 368

sorting by include files, 357

sorting by section, 357

summary vectors, 367

tagging keywords, 360

L

Layering, 51

follow base, 54

follow top, 54

fractions, 54

process, 54

proportional, 54

settings for scale up structure, 155

Layersdefined, 15

LGRdefined, 15

Licenses, 40

Light oil+gas, 72

Liner, 306

Line styles

settings for dynamic data, 227

Local grid refinementdefined, 15

Local grid refinements, 47, 180, 195defined by polygons, 181

defined by surfaces, 181

defined by wells, 181

extending host cell along I, J, K, 184

grid separate zones, 184

grid to well connections, 185

methods, 183

scaling up a property onto the local grid set, 187

setting different parameters for different sources, 185setting source parameters, 184

specifying host cells from sources, 182

upscaling a property, 193

use active filter, 184

zone filter, 184

Local grid sethow to make, 190

inspecting, 192

M

Make aquifers, 195

adding an aquifer, 203

creating new or edit existing, 196

drive direction and vertical extent, 198

properties tab, 202

specifying the model to use, 197

Make contacts, 77procedure, 77

Make fluid model, 66importing a keyword fluid model, 83

Make Horizons, 51process defined, 51

Make rock physics functions, 88capillary pressure, 95

corey correlations, 92

how to make, 100

how to make a saturation function, 98

importing, 97

irreducible saturations, 94

plotting, 97

Reviewing the data, 102

rock compaction function, 89

saturation function, 91

spreadsheets, 95

Make simple grid, 48

Make zones

process defined, 51




Map windowdefined, 15

Menu bar,defined, 15

Modeldefined, 16

Models pane, 25, 26

defined, 16

Multiple drop, 52

Multi-value probe, 134

N

Nodes

defined, 16

Notescomments tab, 34

O

Objects

history, 34

renaming, 34

settings, 33

Observed databubble plots, 234

change the line style in function windows, 236

importing, 210

viewing in a function window, 212

Oil properties, 74

Online Help Manual, 41

Opening

projects, 39

OPF (Open Petrel Format) format, 118

PPanes

cases pane, 26, 27

input pane, 25, 26

models pane, 25, 26

processes pane, 25, 28

results pane, 25, 27

templates pane, 25

windows pane, 26, 29

workflows pane, 25, 29

Perforation, 306

Permeabilities

directional averaging methods, 169

Phase diagrams, 68

Phase pressures

computing, 114

Pillar griddingboundary, defined, 141

cell size, 144

changing the grid orientation, 151

coarsening the grid, 148

concept, 140

defined, 16

excluding faults, 146

faults, defined, 141

geometry and formats, 147

results, 147

segments, defined, 141

settings, 142

throughput problems,

trends, defined, 141

Pillarsdefined, 16

Plottingfluid model, 83

observed data versus the development strategy, 215

rock physics functions, 97

Plot windowcombining view-ports in one plot window, 238

Plug, 307

Polygons

defined, 16

importing, 190

in local grid refinements, 181

in make aquifer, 197

Pore volumesetting minimum, 119




Prediction depletion strategydefined, 337

Prediction development strategyadding new rules, 341

adding new times, 338adding new wells, 338

converting to tabular rule, 342

copy and paste a development strategy, 346

group control, 344

how to add a new rule to an existing

strategy, 349

how to create by using a default strategy, 347

how to define a prediction case, 350

how to make a strategy with a tabular rule, 351

how to view simulation results, 350

linked folders, 339

making a strategy, 336

rule validation, 342

user folders, 339

Prediction mode, 209

Prediction water flood strategy

defined, 337

Pressureentering at separator conditions, 72

Processes pane, 25, 28defined, 16

Project settings, 31

Properties

entering for gas, 73

for gas, 73

for oil, 74

multi-value probe, 134

Scaling up, 163

Proportional layering, 54

QQualitative mode, 250

Quality checking

in scale up structure, 160

of the coarse grid, 156

Quantitative mode, 250

RReference project tool

how to use, 285

Relative permeability

curve for oil-water, 94

Remote job submission, 382

Reservoir conditions

in black oil models, 72

Results3D initial properties, 116

Results pane, 25, 27defined, 16

exporting simulation results, 231

filter results tree, 230

Results viewing, 129

Rock compaction function, 89

how to make, 100

settings, 90

Rock physics functions. See Make rock physics functions

Rules

converting to tabular rule, 342

for the prediction development strategy, 341

validation, 342

S

Saturation

by equilibration, 115

Saturation function, 91how to make, 98

Savingprojects, 39

Scale up. See also Upscaling

Scale up fracture network, 376

Scale up properties

algorithms for discrete properties, 168

applying different methods, 173

averaging methods, 167

how to sample properties from fine grid into coarse grid, 170

process, 163

reviewing in a 3D window, 175




reviewing the upscaled properties, 174

selecting algorithm, 166

Scale up structure,

grid quality check, 160layering, 159

two methods for, 155

Sector modeling, 377capturing boundary conditions for a region, 378

inserting a sector model, 379

Segment filterused in local grid refinements, 184

Segmentsin pillar gridding, defined, 141

Segments (Regions)

defined, 16

Select/pick mode, 37

Sensitivity runs, 209

Separator conditions, 72

Settings

for layering in zones, 155

for objects, 33

for pillar gridding, 142

for project, 31

for rock compaction function, 90

style tab, 33

Simulation casedefine simulation case, 108

importing an existing case, 363

managing, 366

remote job submission, 382


units, 364

Simulation griddefined, 17

making, 139

Simulationsbubble plots for simulation data, 234

change the line style for simulated data in function windows,

236

development strategies, 208

viewing data on streamlines, 241

Simulatorsselecting, 108

Skeletondefined, 17

Skeleton grid, 147

Spreadsheet

for wells, 297

Spreadsheetsfor rock physics functions, 95

to model variation with depth in black oil models, 78

Squeeze, 306

Startwell filter, , 236

Statistics tab, 35

Status bar

defined, 17

Stimulation, 306

Strategies

when initializing model, 116

Streamlines, 235

Style tab, 33

Summation

in scale up properties, 166

Surfaces. See also Horizonsdefined, 17


T

Table

setting up for initial conditions, 76

Temperatureentering at separator conditions, 72

Templateschanging, 34

defined, 17

Templates pane, 25defined, 17

Terminologyused in this manual, 13

Threshold, 251



Time units, 32

Title bar

defined, 17

Toolbardefined, 17

Trajectories, 270

Transmissibilities tab, 119

Transmissibility multiplier

assigning to fault, 58

defined, 17

Trendsdefined, 17


Tuning runs, 209

UUncertainty workflow editor, 29

Units

for time in Petrel, 32

Upscaling, 153

Use active filter


User interface, 24, 41

VValue filter

how to use, 162

Vertical coarseningupscaling, 153

Vertical subdivision, 51two methods for simulation grid, 155

Vertical wellhow to make, 278

V ti l ll i t ti

W

Water cut

defined, 244

Water rates, 244

Weighting

defined, 17

Well bore history, 209

Well completion design, 306

editing completion data, 314

editing completion items, 310

editing existing and adding new completions, 319

how to define equipment, 323

how to edit casing, 326

how to import well completion events, 328

how to insert casing, 324

how to insert perforation, 326

how to make completions using the operations tab, 331

importing event data, 320

inserting a new completion item, 310

organizing data, 312

placing items at depth, 315

quality check, 330

Well datahow to import, 276

importing a well header, 264

importing well path / deviation file, 265

Well filters, 126

Well header

importing, 264

Well manager, 267, 303

Well path

digitizing, 272

Documents

Petrel 2010 Reservoir Engineering Course