PetroMod_2011.1_HeatFlowCalibrationTool_ReferenceGuide-2.pdf

Heat Flow Calibration ToolVersion 2011.1

Reference Guide

PetroMod Version 2011.1 - Heat Flow Calibration Tool Reference Guide

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3 Heat Flow Calibration Tool Reference Guide


Table of Contents

CHAPTER 1: INTRODUCTION ............................................................................................ 6

CHAPTER 2: THE HEAT FLOW CALIBRATION TOOL .......................................................... 8

2.1 OPENING THE HEAT FLOW CALIBRATION TOOL .....................................................................9

2.2 STEP 1: SIMULATION ............................................................................................................13

2.3 SIDESTEP - SETTING UP HEAT FLOW CALIBRATION IN THE SIMULATOR ...................................15

2.4 STEP 2: CALIBRATION ...........................................................................................................172.4.1 Create The Calibrated Heat Flow Maps ........................................................................................ 172.4.2 Defining No-Calibration Areas ....................................................................................................... 19

2.5 STEP 3: POST PROCESSING - SMOOTHING ............................................................................22

2.6 STEP4: EXPORTING THE CALIBRATED HEAT FLOW MAPS .......................................................242.6.1 Export The Maps Directly to PetroBuilder 3D ............................................................................... 242.6.2 Exporting The Maps as ASCII Files .............................................................................................. 24

2.7 ASSIGN THE HEAT FLOW MAPS IN PETROBUILDER 3D ..........................................................26

2.8 SIMULATION WITH THE CALIBRATED HEAT FLOW MAPS .........................................................28

2.9 CHECK THE RESULTS ...........................................................................................................29

APPENDIX A: HELP AND SUPPORT INFORMATION ............................................................ 30

APPENDIX B: GLOSSARY ................................................................................................ 32

Table of Contents 4




CHAPTER 1: INTRODUCTION

The PetroMod software package fully integrates seismic, stratigraphic and geological interpretations

with multi-dimensional and multi-component simulations of thermal, fluid-flow and petroleum

migration histories in sedimentary basins. The PetroMod family offers full 3D hydrocarbon

generation and migration modeling capabilities. The full packages combine the most technically

advanced 1D, 2D, and 3D technologies with a unique degree of usability for the best results of your

petroleum systems analysis.

The Heat Flow Calibration Tool is a fast and effective tool to calibrate 3D models to the temperature

and vitrinite reflectance measurements provided with the wells of a project. The significant benefit is

that you can calibrate all wells at once. The results are written in heat flow maps which can be

exported from the tool and then imported into the 3D model as additional maps.

The tool has been structured in four simple steps: simulation, calibration, post processing and

exporting. The simulation step in the Heat Flow Calibration Tool has been set up with reasonable

default settings to simplify and optimize the heat flow calibration for most models. For experienced

and advanced PetroMod users this function has also been integrated directly into the Simulation

Interface.

Note The benefit of working with the tool from the Simulator Interface is that you can modify the simulation settings, i.e. you can include migration in the simulation, run the simulation on the whole model, modify the pressure settings, etc. These modifications will have an effect on the simulation time. Depending on the size of your model the simulation might take significantly longer. If you are working on a UNIX system and also own a PetroMod parallel processing license, you can perform a parallel simulation from the Simulator Interface on multiple processors.

Running the Heat Flow Calibration Tool from the Simulator Interface only replaces the simulation

step of the tool. All other steps need to be performed directly from the tool.

The following work flow will guide you step-by-step through the heat flow calibration using this tool,

showing you the results in 1D extractions prior to and post calibration.

Introduction 6


Who Should Use This Software?Specialist basin and petroleum system modelers whose responsibilities range from petroleum

resource assessments on a regional scale, to petroleum charge risk assessments on a play or

prospect scale.



CHAPTER 2: THE HEAT FLOW CALIBRATION TOOL

The example model used in this Reference Guide contains 6 wells. Four of the wells have measured

data against which the simulated model can be calibrated. Figure 2-1 shows two plots from a 1D

extraction at a selected well prior to the use of the tool. The plots show the calculated temperature

(red) and vitrinite reflectance (blue) trends as well as the measured calibration data (purple icons) for

that well. There are significant discrepancies between the calculated trends and the calibration data.

Figure 2-1: Plots showing calculated temperature and vitrinite reflectance trends and the calibration data.

The Heat Flow Calibration Tool can be used to optimize the fit between the calculated values and the

measured data. The tool performs statistical calculations based on PetroRisk for an area of interest

which is automatically created (and can be manually modified) around the wells. The calculated heat

flow maps can be exported back into PetroBuilder 3D and assigned as boundary conditions. The

model can then be simulated with the newly generated maps.

INFO: IMPORTANT• The tool is map based, trends MUST be converted to heat flow (HF) maps to be used with this

tool. • Pseudo wells can be used as calibration data.

The Heat Flow Calibration Tool 8


2.1 Opening The Heat Flow Calibration Tool1 The tool is opened via the PetroMod Command Menu. Open the Petro* tab and click once on

the Heat Flow Calibration icon to open the tool (alternatively, click Petro* on the Menu bar and

then Heatflow Calibration).

Figure 2-2: Opening the Heat Flow Calibration Tool.

2 A dialog box will open where you need to select the model. Browse for the model and click

Open.

3 The Heat Flow Calibration Tool will open as shown in Figure 2-3.



Tree

Heat Flow Map

Prognosis

Heat Flow TrendInfo pane

Figure 2-3: Heat Flow Calibration Tool interface.

Interface FeaturesThe interface contains the following features:

Tree

• The first three items on the Tree are the three calibration steps: Simulation, Calibration, and

Post Processing. To simplify the procedure, already performed steps are highlighted in color

and certain option-related buttons will only be sensitive on the Toolbar when they are applicable.

• The next item on the Tree, Heat Flow Map, enables you to change the appearance of the heat

flow map.

• The next item, Wells, lists the well lists for your model. Figure 2-4 shows a model with six wells.

Four of the wells have calibration data - Wells 1, 2 and 4 have temperature and vitrinite

reflectance data (T and V) and Well 7 has vitrinite reflectance data only (V).



Figure 2-4: Wells listed on the Tree in the Wells folder.

To view and edit the AOIs around the wells, you need to work with the Simulation Settings - Step 1

dialog box, which is displayed in the Info pane by default when opening the Heat Flow Calibration

Tool. Select Show Area of Interest to display AOIs around wells with calibration data, see Figure 2-

5 (see 2.2 "Step 1: Simulation" for a description of all options in the dialog box). The AOIs around the

wells are the areas on which the calibration calculations will be based. Areas of interest are only

defined around wells with calibration data.

Click to show AOIs

Figure 2-5: Heat flow map with AOIs around wells.

In this example, AOIs are displayed for Well 1, Well 2 and Well 4. Well 7 also has calibration data,

but the well lies outside the model AOI, i.e. the AOI that was assigned in PetroBuilder 3D. Only wells

inside the model AOI are considered by the Heat Flow Calibration Tool. Please refer to the

PetroBuilder 3D User Guide for more information on defining and assigning the model AOI.



Heat Flow Map

The center of the interface shows a bird’s eye view of the heat flow maps that are assigned in

PetroBuilder 3D. Use the Event scroll box above the Tree to show maps for different events:

Figure 2-6: Select an event to view the corresponding heat flow map.

The maps cover the Area of Interest (AOI) that has been assigned in PetroBuilder 3D (model AOI). In

this example (see Figure 2-5), Well 7 and Well 5 lie outside the model’s AOI and will NOT be

considered by the tool.

Prognosis

This part of the interface remains empty until a simulation run has been performed. After simulation,

the pane displays a prognosis that shows the plotted master run and suggested best fit for present

day heat flow related to the depth and taking into consideration the temperature values for the

respective well.

Heat Flow Trend

The bottom pane shows the evolution of the heat flow through time for the currently selected well.

Click a different well on the Tree to view the respective trend for that well.

Info pane

When you click on certain items in the Tree, e.g. Simulation, Wells, etc. dialog boxes with further

options appear in the Info pane.



2.2 Step 1: Simulation1 Click Simulation - Step 1 on the Tree to open the Simulation Settings - Step 1 dialog box in

the Info pane (if it is not already open). Set the options as required:

Figure 2-7: Simulation Settings - Step 1 dialog box

• Show Area of Interest (AOI): Tick to display the AOIs around the wells on the heat flow map.

• AOI Around Wells in Unsamp. Grid Points: Choosing a larger AOI around the wells

incorporates wider (lateral) 3D effects in the calculation.

• HF Uncert. [unit]: The Heat Flow Uncertainty value depends on the agreement of the heat flow

trend with the measured well data. The closer the trend is to the measured data, the less

uncertain the calibrated heat flow trend, and therefore a lower value can be set. These values

define the limits within which the calibration is calculated.

2 Click the Perform Simulation Runs button on the Menu bar. The simulation will start. A

box will open to remind you about the possibility to run an individually modified simulation from

the Simulator Interface. Click Start to confirm the run using the Heat Flow Calibration Tool. A

report window will open in which you can follow the progress of the simulation. First, the model is

calculated with lithology and thermal evolution. After that, eight risk runs are performed which

are usually sufficient for reaching a sensible adaptation of the heat flow curve.

When the simulation run ends the display switches back to the original window with the map in the

center, see Figure 2-8.



Figure 2-8: Heat Flow Calibration Tool after first simulation run.

• The Simulation Settings - Step 1 dialog box summarizes the settings for the performed risk

runs, so that you can easily check what you did before if you want to modify the settings for

another one.

• The Heat Flow Trend displays the master run heat flow in yellow and the suggested calibrated

heat flow in black.

• The Prognosis pane on the right shows the plotted master run (green) and suggested best fit

(black) present day heat flow related to depth and taking into consideration the temperature

values for the respective well (wells can be changed by selecting a well on the Tree). The red

crosses indicate the measured well data.

• The Tree now contains additional entries: Heat Flow Trend, Temperature and Vitrinite

Reflectance. Clicking Heat Flow Trend opens the corresponding dialog box where you can

change the colors of the displayed trends. Clicking either Temperature or Vitrinite Reflectance

switches the overlay in the Prognosis pane.



2.3 Sidestep - Setting up Heat Flow Calibration in the SimulatorThe simulation step can also be performed from the 2D/3D Simulator. Running the simulation from

the Simulator enables you to modify the simulation settings, e.g. perform parallel runs, include

migration in the simulation, run the simulation on the whole model, modify the pressure settings, etc.

After simulation, open the Heat Flow Calibration Tool and proceed with the next steps as described

in 2.4 "Step 2: Calibration".

Notes:

• You can only modify the AOI around the wells and the heat flow uncertainty in the Simulation Settings info box in the Heat Flow Calibration Tool, see 2.2 "Step 1: Simulation". If these settings have changed, click the Save button on the Toolbar of the Heat Flow Calibration Tool and close the tool.

• To include migration in the simulation run, enter 0 (no AOI) in the AOI Around Wells field in the Simulation Settings - Step 1 dialog in the Heat Flow Calibration Tool. The whole model will be processed.

1 Ensure the Heat Flow Calibration Tool is closed. Then open the Simulator by clicking once on

the respective icon on the 3D tab of the PetroMod Command Menu. Open the model.

2 Expand the Risk folder on the Simulation 2D/3D Control Panel and tick the HF Calibration

Tool option as shown in Figure 2-9.

Figure 2-9: Selecting the HF Calibration Tool in the Simulator.

3 The HeatFlow dialog will open as shown in Figure 2-10. Modify the settings as required (see the

PetroMod 2011.1 Simulator User Guide for more details on all simulator options).



Figure 2-10: The HeatFlow dialog in the Simulator.

4 Click the Run button on the Toolbar of the Simulator and confirm that you want to run the

simulation.

5 When the simulation has finished, close the Simulator. Open the Heat Flow Calibration Tool

and proceed with 2.4 "Step 2: Calibration"



2.4 Step 2: CalibrationAfter running the simulation several buttons will become active on the Toolbar of the Heat Flow

Calibration Tool:

• The Define “no-calibration” areas button allows you to graphically select areas that will

be left unchanged when the new heat flow maps are generated. This can be useful, for example,

when the calculated temperature data for a certain well already fits the calibration data.

• Clicking the Calc. HF Maps button generates new heat flow maps for each event based on

the results of the simulation run.

• Several inactive buttons (Undo, Redo, Smooth HF Maps) will be available after making graphic

modifications on the map.

2.4.1 Create The Calibrated Heat Flow Maps1 Click Calibration - Step 2 on the Tree to open the Calibration - Step 2 dialog box in the Info

pane:

Click to open dialog box.

Figure 2-11: The Calibration - Step 2 dialog box.

2 Adjust the options as required:

• Show “No-Calibration” Area(s): Displays the areas that will not be used for calibration (see

2.4.2 "Defining No-Calibration Areas" for information on defining areas of no calibration).



• Use Only Wells Displayed in Map View: If you deselected wells on the Tree, use this option to

exclude them from the calibrated maps.

• Show HF Shift (Calibration) Area: This option toggles the display of the AOIs on/off

• Size of Heat Flow Shift Area: This field enables the user to vary the size of the AOI around the

well(s) and thereby the impact of the heat flow shift on the whole map. Pay attention to the

following:

• A certain width of the heatflow peak must be ensured, otherwise the heat inflow or outflow

might distribute laterally before affecting the calibration values. In general, the size of an AOI

should be approximately twice the maximum vertical depth difference between the calibration

values of the well and the depth where the basal heat flow is applied.

• When AOIs overlap, an average heatflow is applied to the overlapping area. The result might

not reach the prognosis because the wells could interfere with each other in the calibrated

model.

• Max HF and Min HF: Limiting values for the trend.

3 Click the Calc. HF Maps button on the Toolbar to create the new heat flow maps. The

calculated temperature adjustments from the simulation run will be applied to the AOIs around

the wells, the rest will be interpolated. The tool creates one map per event. In Figure 2-12 five

maps have been created. Use the Select Event scroll box to scroll through the created maps.



Figure 2-12: Calibrated heat flow map.

A new entry called Calibr. Heat Flow Map is listed on the Tree and the corresponding dialog

automatically opens in the Info pane. The dialog provides options for customizing the display of the

map (color, isolines, colormap, etc.) as well as changing the heat flow unit.

The calibrated heat flow maps can now either be exported (see 2.6 "Step4: Exporting The Calibrated

Heat Flow Maps") or processed further as explained in 2.5 "Step 3: Post Processing - Smoothing".

Note: There is no Undo function to undo the creation of the calibrated heat flow maps. However, If you close the Heat Flow Calibration Tool before exporting the maps and re-open it again, the simulation data will be saved, but not the calibrated heat flow maps.

2.4.2 Defining No-Calibration AreasThe Heat Flow Calibration Tool enables users to mark areas in a map to be excluded from the

calibration calculation. The marked area is excluded from all time steps.

1 Click the Define “no-calibration” areas button . The cursor will change to crosshairs.

Draw a polygon to define the area to exclude from the calibration process. Close the polygon by

right-clicking in the map and clicking Close, see Figure 2-13. To move the polygon, simply drag

it to a new location.



Figure 2-13: Defining a no-calibration area.

2 To assign the polygon as a no-calibration area, right-click in the polygon and click Define “no-

calibration” area. The area inside the polygon will be marked by red crosses, see Figure 2-14.

Figure 2-14: Red area will be excluded from the calibration.

3 Click the Calc. HF Maps button again to recalculate the maps. Figure 2-15 displays the effect of

the drawn polygon after re-calculating the map and hiding the no-calibration area (see section

2.4.1 for information on showing/hiding the no-calibration area). Compare it with the heat flow

map in Figure 2-12.



Figure 2-15: Recalculating heat flow maps with the no-calibration area.

These modifications can be undone and redone with the corresponding buttons on the Toolbar and

by re-calculating the maps: Click the Undo button on the Toolbar to undo the creation of the

polygon. Then click the Calc. HF Maps button again to recalculate the map without no-calibration

area.



2.5 Step 3: Post Processing - SmoothingThis step is optional. Note there is no direct undo to this step. If you want to undo the smoothing,

click the Calc. HF Maps button again.

1 Click Post Processing - Step 3 on the Tree to open the corresponding dialog box in the Info

pane:

Click to open the Post Processing dialog box

Figure 2-16: Post Processing options.

The dialog box contains the following options:

• Smoothing Steps: The higher the number, the flatter the map.

• Apply Smoothing to Selected Event Only: Activate this option to apply smoothing to the

selected event only. If you do not select this option, all maps will be smoothed simultaneously.

2 Click the Smooth HF Maps button on the Toolbar. A Warning box will appear:

“Smoothing might (drastically) reduce the quality of calibration!”. Click Continue. The map

will be recalculated. Figure 2-17 shows the heat flow map before smoothing and after

smoothing.



Before smoothing After smoothing

Figure 2-17: Heat flow maps before and after smoothing.

The changes are also displayed in the heat flow trend as shown in Figure 2-18. The yellow line

indicates the heat flow map from the master run (simulation), the black line the suggested best fit, the

blue line the smoothed calibrated trend, which deviated from the suggestion.

Note: heat flow from input model = yellow; heat flow from output model = green. In this example there is heat flow data from the input model only.

Figure 2-18: Heat flow trends for a selected well. The blue trend shows the effect of smoothing.

3 Users need to decide which maps to use (smoothed or non-smoothed). If the non-smoothed

maps are preferred, undo the smoothing by clicking the Calc. HF Maps button again to reach

the point prior to smoothing.



2.6 Step4: Exporting The Calibrated Heat Flow MapsThe calibrated heat flow maps can be exported in two possible ways: either directly to PetroBuilder

3D, or as ASCII files.

2.6.1 Export The Maps Directly to PetroBuilder 3D1 On the Menu bar of the Heat Flow Calibration Tool click File followed by Add Heat Flow

Maps to Input Data:

Figure 2-19: Export the heat flow maps directly to PetroBuilder 3D.

2 A warning window will open: “PetroBuilder 3D must be closed - Heat flow maps will be

added to additional maps!”. Ensure that PetroBuilder 3D is closed and click Continue. The

next time you open PetroBuilder 3D, the maps will be listed in the Boundary Conditions >

Heatflow > Heatflow > HF Maps folder on the Model pane.

3 Close the Heat Flow Calibration Tool.

2.6.2 Exporting The Maps as ASCII Files1 On the Menu bar of the Heat Flow Calibration Tool click File followed by Export Heat Flow

Maps in ZMap Ascii Format:

Figure 2-20: Export the heat flow maps as ZMap Ascii files.



2 The Select Export Folder dialog will open. Select the folder to where the maps will be exported

and click Choose.

3 A warning box will ask whether it is ok to overwrite existing ZMap files in that directory. Click

Continue. The Heat Flow Calibration Tool exports a calibrated heat flow map for each event, for

which a heat flow map was previously assigned in the Boundary Conditions of PetroBuilder 3D.

4 Close the Heat Flow Calibration Tool.



2.7 Assign The Heat Flow Maps in PetroBuilder 3DThe calibrated heat flow maps now have to be assigned to the boundary conditions in PetroBuilder

3D before the model can be simulated again.

1 Open PetroBuilder 3D and open the model.

2 If you exported the maps directly to PetroBuilder 3D, they will be located in the Boundary

Conditions > Heatflow > Heatflow > HF Maps folder on the Model pane as shown in Figure 2-

21. The grey icon indicates they are not assigned.

Calibrated heat flow maps from the Heat Flow Calibration Tool.

Figure 2-21: The exported calibrated heat flow maps on the Model pane.

If you exported the maps as ASCII files, import them using the File > Import Files command.

The files will be imported into the Drafts folder on the Model pane. Drag and drop them to the

Boundary Conditions > Heatflow > Heatflow > HF Maps folder.

3 Double-click on Heatflow in the Model pane to open the Heatflow table:

Double-click to open the Heat Flow table

Figure 2-22: Open the Heat Flow table.



4 Replace the existing heat flow maps with the calibrated maps. To replace a map, select the map

on the Model pane and click the blue arrow to assign it in the table.

Original heat flow maps Calibrated heat flow maps

Figure 2-23: The Heat Flow table with original and calibrated heat flow maps.

Please refer to the PetroBuilder 3D User Guide for more information on assigning heat flow maps.



2.8 Simulation With The Calibrated Heat Flow MapsAfter assigning the calibrated heat flow maps, simulate the model again. Ensure that the simulation

settings have not changed since the last simulation run to be better able to compare the results pre

and post calibration. Run the simulation.



2.9 Check The ResultsNow perform a 1D extraction on the simulated model and compare the results with the non-

calibrated model. Figure 2-24 shows another 1D extraction at the same well that was used for the 1D

extraction in the original model in Figure 2-1. The new temperature and vitrinite reflectance trends

are much closer to the measured data than before.

Figure 2-24: Temperature and vitrinite reflectance after simulation with calibrated heat flow maps.

Note: The calibration procedure balances all data, i.e. vitrinite reflectance and temperature data from all wells. If the data are inconsistent, the calibrated trends could lie somewhere “in between” both sets of calibration data.



APPENDIX A:HELP AND SUPPORT INFORMATION

PetroMod 2011.1 is provided by © Schlumberger. The software has been designed by the

Schlumberger Aachen Technology Center (AaTC).

PetroMod SupportFor general questions concerning PetroMod please follow the standard procedure within the

Customer Care Center via the SIS support portal at https://support.slb.com. Choose New

incident, then select PetroMod as the Product and the respective module as the Product module.

Your question will be forwarded to the proper support engineer.

Additional Help InformationAlso, PetroMod provides the following help information:

• The PDFs of the user guides (often including sample data), installation guide, and release

notes can be downloaded from https://support.slb.com (PetroMod Documentation).

• Information windows are opened by clicking the question mark button. They provide

detailed help concerning the respective environment of that question mark.

• Tool tips under selected elements.

• Online-help provided via Help on the menu bar of each respective PetroMod module.

30




APPENDIX B:GLOSSARY

The following is not an all encompassing petroleum systems glossary, but explains in short the most

important terms. For additional information on theory and background of Petroleum Systems

Modeling, we recommend Thomas Hantschel, Armin I. Kauerauf, Fundamentals of Basin and

Petroleum Systems Modeling, Springer, 2009 or visit PetroMod on www.slb.com.

Accumulation: The phase in the development of a petroleum system during which hydrocarbons migrate into and remain trapped in a reservoir.3

API gravity: The American Petroleum Institute standard for expressing the specific gravity of oil. API gravity = 141.5/(density)-131.5.4

Breakthrough Point: The point at which the seal fails because the column pressure exceeds the seal capability. [...] Leakage and breakthrough are important processes reducing the trapped volume.1

Buoyancy: Describes the gravitationally powered ascent of relatively low density materials, such as hydrocarbons. The overall direction of migration [of hydrocarbons] is known to be vertical due to buoyancy.1

Capillary Entry Pressure (Cap Pressure): The column height of an accumulation is balanced by the capillary entry pressure of the corresponding seal. [...] It is usually given by mercury-air values in lithological data bases or empirical equations and can be converted to oil-water and gas-water values with interfacial tension values of oil-water and gas-water.1 Petroleum Systems Quick Look uses oil-water as input data.

CGR: Condensate Gas Ratio1

Charge: Petroleum or hydrocarbon charge concerns the whole concept that petroleum can form, migrate, and accumulate in a body of sedimentary rocks (source rock, maturation factors, migration, seal and trap). When all factors combine, hydrocarbons start to fill up or charge the pore spaces of the reservoir rock.

Closure: The vertical distance from the apex of a structure to the lowest structural contour that contains the structure. Measurements of both the areal closure and the distance from the apex to the lowest closing contour are typically incorporated in calculations of the estimated hydrocarbon content of a trap.3 It is easy to construct the shape of a closure by cutting the reservoir with a horizontal plane through the spill point.1

Drainage Area: Also called fetch area. All hydrocarbons entering the carrier in the same drainage area migrate to the same trap. Hydrocarbons entering the carrier at other locations migrate to other traps. Each trap belongs to one drainage area and vice versa.1

32


EOS: Equation of state, see PVT.

Expulsion Efficiency: Petroleum Systems Quick Look calculates the generation for each oil generating cell, but how much remains in the cell after generation? Parts remain in the cell due to adsorption saturation. It also allows you to account for migration losses.

Fault: A break or planar surface in brittle rock across which there is observable displacement.3

Within Petroleum Systems Quick Look a fault must be represented by a single line at which the displacement occurs on the top map. Within Petrel, faults can be represented by numerous visual items, including most commonly lines, sticks, polygons, and surfaces. The only fault lines allowed within Petroleum Systems Quick Look are polygon lines representing the fault at the level of the top map used for the controller calculation.

Flash calculation: See PVT.

Generation-migration-accumulation: One petroleum system process that includes the generation and movement of petroleum from the pod of active source rock to the petroleum show, seep, or accumulation. The time over which this process occurs is the age of the petroleum system.2

Geothermal Gradient: Heat conduction is defined as the transfer of thermal energy by contact according to thermal gradients. Heat flow analysis which is based on a constant thermal gradient is a very rough approximation. The thermal gradient determines the increase of heat with depth.1

GOR: Gas Oil Ratio, the ratio of produced gas to produced oil.3

Grain Density: The density of the grains in a formation or core sample. As used in log and core analyis, the term ‘grain’ refers to all the solid material in the rock, since, when interpreting the measurements, no effort is made to distinguish grains from other solid material. The grain density of core samples is calculated from the measured dry weight divided by the grain volume. In logs, grain density is calculated from the density log using an estimate of porosity and knowledge of the fluid content.3

Heat Flow: The heat flowing from the Earth’s interior through a unit area at the surface, generally in units of mWm-2.4 Temperature and heat flow are the basic variables for heat conduction. Temperature is the state variable and heat flow is the corresponding flow variable. A temperature difference (or gradient) causes a heat flow and the heat flow decreases the temperature difference. The heat flow is controlled by thermal conductivity and the temperature response by the heat capacity.1

Hydrogen index: The hydrogen index (HI) is a Rock-Eval pyrolysis parameter. It is the mass of hydrocarbons per mass of TOC (total organic carbon) which can be generated from kerogen by thermal cracking.1

Injection: Point or area from where the vapor and/or liquid has arrived at the reservoir structure. Within Petrel this can be represented by point data or by a closed polygon.

Kerogen: A bituminous material, found in oil shales and other sedimentary rocks, which is composed of organic matter and can yield oil on distillation.4 The naturally occuring, solid, insoluble organic matter that occurs in source rocks and can yield oil upon heating. Kerogens

33 Heat Flow Calibration Reference Guide


have a high molecular weight relative to bitumen, or soluble organic matter. Bitumen forms from kerogen during petroleum generation. Kerogens are described as Type I, consisting of mainly algal and amorphous (but presumably algal) kerogen and highly likely to generate oil; Type II, mixed terrestrial and marine source material that can generate waxy oil; and Type III, woody terrestrial source material that typically generates gas.3

Liquid or vapor injection map [Mtons/km^2]: A graphic depiction of the points or areas from where liquid or vapor has entered a layer. The amount of injected liquid or vapor is represented on a color scale. These maps are generated by the calculation initiated on the Generation maps tab. The user can also use his own maps.

Liquid [MMbbls] or vapor [Mm^3] volume: Petroleum Systems Quick Look uses the simple volume, mass, density equation (V = m / ρ) to calculate liquid or vapor volume in a layer. A value can be typed in the vapor or liquid volume fields or a surface can be used. In Petroleum Systems Quick Look these types of property surfaces are often called overlays. In Petrel these can be represented by numerous types of items such as surfaces, geocellular modeled properties, and attributes. For use within Petrel only property surfaces can be dropped into the Quick look controller.

Map (Top Map & Base Map): The stratigraphic horizon represented by a surface. Top map refers to the top of the stratigraphic unit, the base map refers to the base of that stratigraphic unit (therefore equivalent to the top of the next stratigraphic unit). In Petrel the term used is ‘surface’, and these are found under the Input pane. Within Petroleum Systems Quick Look the base map term is used on the Generation maps tab in reference to the base of the source rock and on the Charge tab for the base of the reservoir.

Petroleum system: The essential elements and processes as well as all genetically related hydrocarbons that occur in petroleum shows, seeps, and accumulations whose provenance is a single pod of active source rock. Also called hydrocarbon system and oil and gas system.2

Porosity: The percentage of pore volume or void space, or that volume within rock that can contain fluids. Porosity can be a relic of deposition or can develop through alteration of the rock. Petroleum Systems Quick Look does not distinguish between effective porosity and total porosity.3

PVT: Pressure, volume, temperature. Basin wide predictions can only be performed with a more precise specification of the pressure volume temperature relationships of the fluids. These relationships are called equations of state (EOS). The EOS used in Petroleum Systems Quick Look is Soave-Redlich-Kwong. Phase amounts and compositions can be calculated by minimization of thermo-dynamical potentials, namely the Gibbs free energy, in multi-compositional resolution. The resulting algorithm is called a flash calculation.1

Quick look controller: This is the dialog box which appears when Petroleum Systems Quick Look has been selected. All calculations are performed within this dialog box.

Reservoir rock: A subsurface volume of rock that has sufficient porosity and permeability to permit the migration and accumulation of petroleum under adequate trap conditions. An essential element of the petroleum system.2

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Seal rock: A shale or other impervious rock that acts as a barrier to the passage of petroleum migrating in the subsurface; it overlies the reservoir rock to form a trap or conduit. Also known as roof rock and cap rock an essential element of the petroleum system.2

Seal failure: See breakthrough point.

Source Rock: A rock unit containing sufficient organic matter of suitable chemical composition to biogenically or thermally generate and expel petroleum. An essential element of the petroleum system.2

Spill point/Spill path: The structurally lowest point in a hydrocarbon trap that can retain hydrocarbons. Once a trap has been filled to its spill point, further storage or retention of hydrocarbons will not occur for lack of reservoir space within that trap. The hydrocarbons spill or leak out, and they continue to migrate along the spill path until they are trapped elsewhere.3

Thermal conductivity: Describes the ability of material to transport thermal energy via conduction. For a given temperature difference a good heat conductor induces a high heat flow, or a given heat flow maintains a small temperature difference.[...] The unit is W/m/K. [...] The bulk thermal conductivity is controlled by conductivity values of rock and fluid components.1

Thickness: Here, true vertical thickness (as opposed to true stratigraphical thickness): the thickness of a bed or rock body measured vertically at a point. The values of true vertical thickness in an area can be plotted and contours drawn to create an isochore map.3

TOC (Total organic carbon content): The total content of organic matter (kerogen and bitumen) is usually given in terms of the TOC in mass%. It is the ratio of the mass of all carbon atoms in the organic particles to the total mass of the rock matrix. Hence, it is a concentration value and one needs the total rock mass of the source rock for conversion into generated and expelled petroleum masses.1

Transformation ratio: The quantitative transformation of the original organic material based on the total organic carbon content and hydrogen index in the source rock.1

Trap: Any geometric arrangement of rock regardless of origin that permits significant accumulation of oil, or gas, or both in the subsurface and includes a reservoir rock and an overlying or updip seal rock. Types are stratigraphic, structural, and combination traps. Trap formation is one of the petroleum system processes.2

Water depth map: In Petroleum Systems Quick Look, present day water depth maps are used to ensure a) the correct geometry of the reservoir; and b) correct calculation of the burial depth. 1

Sources:

1 From Thomas Hantschel, Armin I. Kauerauf, Fundamentals of Basin and Petroleum Systems Modeling, Springer, 2009

2 From Leslie B. Magoon, “Petroleum System: Nature’s Distribution System for Oil and Gas”, Encyclopedia of Energy, Volume 4, Elsevier Inc., 2004, p. 823-836.



3 www.glossary.oilfield.slb.com

4 Philip Kearey, The New Penguin Dictionary of Geology, Second Edition, Penguin Books, London, 2001.

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Documents

PetroMod_2011.1_HeatFlowCalibrationTool_ReferenceGuide-2.pdf