Geoscience for the Fdp 2015_2

8/9/2019 Geoscience for the Fdp 2015_2

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GEOSCIENCE for theField Development ProjectSome guidance

Geoscience for the FDP 1


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Outline

Project aims

Data

Analysis and Outputs

Marking criteria

Geological conceptual model

Further advice



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Project Aims

Design or Development Project

Aim to produce economically justified development plan

Geoscience affects everything!

Shape and architecture affect volume and production strategies

Properties affect volumetrics and reservoir engineering

Stratigraphic column, rock types and pressures affect drillingchoices

Etc…



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Data

Data derived from North Sea fields

BUT changed

Geology is North Sea, but other locations may be given forenvironmental or economic considerations (use North Seastratigraphy, literature for the geology sections)

By all means look for analogue fields in theliterature. HOWEVER, even if you think you find ‘your’ fieldin the literature, remember the changes and that you onlyhave some of the data from that field and that anystatement you use in your report or presentation has to be

backed up by the evidence you see IN THE DATASET youhave.



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Data

~6 wells

Mudlogs, wireline, core plug measurements, corephotos, descriptions, fluid samples, well tests(some)… beware of data quality.

Top structure map

Simplified

Seismic line

For big picture, reference only. Not for extrainterpretation or well ties.


Core Store VISIT –2 people per team


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Aim is to produce conceptual model of the reservoir,layering and structure, that will be converted for youinto a computer model for use in simulation.

Interpretations MUST be backed up by YOUR EVIDENCE

from the data provided to you, and your reasoning onthe basis of that data.



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Depositional Environment

Gives connectivity, and orientation of any elongate bodies

Stratigraphic correlations, connectivity and layering

Correlations in TVD?; always label with amount ofvertical exaggeration used

Isopach maps?

Cross-sections (do not use vertical exaggeration)

Conceptual model

Volumetrics – requires statistics and other properties.


NAzimuth

Major Axis

Minor Axis

Major AxisMinor Axis

Major = Minor Axis

SheetsEg: Turbidite Sheets

ChannelsEg: Fluvial/Turbidite

Shallow marineShoreface/Beach

Palaeocurrent

Shoreline


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Issues to consider

Porosity and permeability distributions (vertical and horizontal) Spatial variability, both measurable and predicted based on

depositional environment…

Diagenetic effects

Core-to-log relationships

Geological Statistics – suitable averages Geomechanical issues (e.g. rock strength, wellbore stability

variations from background due to faulting, folding, fracturing)

Geochemical issues? (e.g. wettability)

Uncertainties

All projects have uncertainty

Need to identify uncertainty

Develop plan for dealing with or resolving uncertainty


F r e q u e n c y

Variable


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Teamwork

Geological model will require integrated analysis of puregeology data, petrophysical data, well testing data and

some reservoir engineering data. Therefore if you assign these ‘roles’ to different team

members, then you must ensure that these individualscommunicate and collaborate to create the model.

ALL team members should understand and agree with the

conceptual model produced.



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Standardized Reservoir Description – works from general

to specific information Location

Trap

Fluid

When discovered, current status, any production history

Reservoir rocks (lithology, environment, age)

Correlations/models

Column height and/or OWC

Fluid properties, volumetrics

Comments, comparisons, analogues



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Images to include in your reports

Maps (very important)

Cross-section (no vertical exaggeration)

Stratigraphic column

Correlations (stratigraphic and structural; state VE used) Rock images – cores and also images from the field!

All those lovely outcrops from Inverness!



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Marking Criteria

A Grade:

“Innovative evaluation of the geological data, discussion ofdepositional environment, geological statistics, STOIIP,including structural analysis and multiple correlations of thereservoir. Creation of an integrated reservoir model.Analysis of uncertainties. Excellent diagrams.”



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Geological Conceptual Model

A conceptual model is required to be provided to an ‘expert’ who will create the ECLIPSE input files for you.

You will need to provide a number of diagrams,(correlations, maps) as well as statistics, well locations,grid sizes and other information to create this model.

There will be a form that you will fill in to provide the

expert with the information required… (provided at endof week 1/start week 2 ish)

Your geological advisor (tutor) will need to sign off onthe completed conceptual model.



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Spreadsheetto fill in thebasic data



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OTHER THINGS:

Formation Tops (well to well correlation)

Base of reservoir (parallel, not parallel, flat?)

Model size, gridding

Faults

Horizons, Zones, Layering

OWC

Facies, based on well logs – cut-offs?, properties (statistics)

Variograms (horizontal and vertical facies variation) these are going to be theoretically based on what your

understanding of the depositional environment is: variogramsbased on data only give vertical variation

See Chapter 9 G11PG for details



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Further Advice

VISION Gary gives an introductory video

Ppt shows with details about how to fill in the model spreadsheetsand how to create the data necessary

Geoscience for Petroleum Engineering (G11PG) – all the notes and

the ppt shows and the advice on VISION will help you to build themodel!

Advice on research generally

Data

Discussion

Literature Remember your conclusions can only be based on the data available

to you and the analysis you have done on that data (no statementsbased on literature sources). However you may search the literatureto help you or to provide comparisons for your field. The fields areall based on North Sea fields, so use articles or papers on North Seageology.


Documents

Geoscience for the Fdp 2015_2