A Perspective on Experience on U.S-Norwegian Co-operation on EOR at COREC

Centre at Rogaland and University of Bergen

David R. Zornes

Manager – Reservoir Mechanisms Group

Bartlesville Technology Center

Outline of PresentationOutline of Presentation

• History of COP and Norway

• Primary Areas of Research – Technical Needs and Issues are Primary Drivers

• Why Cooperation is Our Practice

Ekofisk Research Timeline

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450

Preliminary EOR Lab Tests

Initiate Waterflood in Tor Fm. Based on Initial Characterization.

Expand Waterflood with Updated Lab & Modeling Results.

Subsidence Observed. Start Rock Mechanics Testing & Modeling

Ekofisk II EOR Screening.

Key Research Directions

• Improved Recovery Methods.– Mechanisms and Endpoints.– CO2, HC WAG, MIOR, Imbibition Enh., Air

• Subsidence and Compaction.– Recognition and Forecasting.– Field Monitoring & Fully Coupled Modeling

• CO2 Sequestration – CH4 Production from Hydrates.

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10

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1971 1976 1981 1986 1991 1996 2001

Ekofisk Field

Improved Waterflood Performance

• Initial Studies Suggested Waterflood Would NOT Be Very Successful.

• After Successful Pilot – Lab and Theoretical Studies Focused on Mechanisms and Endpoints.

• Recovery Factor Improvements.

MRI Imaging of Fluids Crossing Fracture in Chalk

• Mechanism for Crossing Strongly Dependent Upon Chalk Wettability.

• How and When Crosses Fracture to Next Block is Critical Information in Simulation Model.

A B

Water Wet Less Water Wet

EOR Evaluation Studies Laboratory & Reservoir Simulation

1998 Study for NPD– HC WAG 6% Recovery Inc. Most Feasible in

Current Environment.– N2 WAG Not Economical.

– CO2 WAG 6% Recovery Inc. Requires CO2 Source. Current COREC Project.

– Air Injection Good Recovery – Last Stage. EU Thermie Project Involving Rogaland, Bath and Contractors.

– MEOR Low Recovery but Inexpensive.

Subsidence of Ekofisk Field

• Recognized in 1984.

• Engineering Response – Jack Up Platforms.

• Research – Fundamentals of Chalk Compressibility Subsidence Modeling/Forecasts.

1978

1986

Chalk Rock Mechanics

• Laboratory Stress / Strain Tests Determine Extent of Potential Compaction.

• Incorporated into Subsidence Model.

• BTC – HiS Laboratory Collaboration.

18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50

Initial Porosity, %

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Axia

l Stra

in @

6,0

00 p

si E

ffect

ive

Axia

l Stre

ss

Measured strains for water-wetted, water-weakened chalk

Measured strains for waterfree Ekofisk chalk

Model water-wetted Ekofisk chalk

Model waterfree Ekofisk chalk

Eldfisk waterfree chalk

Eldfisk water-weakened chalk

Ultimate Axial Strains at 6 kpsi for Ekofisk & Eldfisk Reservoir ChalksMeasured Data and Models for Waterfree and Water-weakened Chalks

30%30%

44%44%

7x7xStrStrainain

Subsidence Modeling

Ultimate Subsidence Risk Profile(Final Model Parameters)

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Subsidence (m)

Cu

mu

lativ

e P

rob

abili

ty

P10=9.5m

P50=14m

P90=19m

North Sea Ultimate Subsidence - 2029

CO2 Sequestration – Hydrate Production Research

• University of Bergen – ConocoPhillips Collaborative Laboratory and Theoretical Study.

• State-of-Art Research Draws on Expertise from Each Group.– Form and Produce Gas

Hydrates in Lab.– MRI Monitor Reaction

Rates and Paths.

CH4 Gas

Water-Saturated Core

Hydrate

Collaboration and Training with Norwegian Universities

• Students Worked on Ekofisk-Related Projects at BTC Since 1980’s – Numerous MS/Dipl. Degrees, 8 Ph.D.’s (Including Several Current Faculty).– NTNU – Dept. of Petroleum Engineering.– University of Bergen – Dept. Physics.– Høgskolen i Stavanger – Dept. Petrol. Eng.

Industry-Supported Research

• Joint Chalk Research. (1970’s – Current). Broad-Based Programs with Emphasis on Industry-University Collaboration. Phillips/CoP as Major Participant in All Stages.

• University Research Centres– CIPR (University of Bergen)

– COREC (University College Stavanger)

• Ekofisk Area PL018 Co-Venturers Sponsored Internal Research.

Lessons from Ekofisk-Related Research on Improved Recovery

• Well-Defined Goals: Problems Linked to Fundamental Questions.

• Long-Term: Allowed for False Starts, Change in Direction.

• Multi-Disciplinary: Left “Business as Usual” Behind, Overcame Tradition and Bias.

Advantages of CooperationAdvantages of Cooperation

• Develop Additional Expertise

• Multi-Discipline Approach

• Longer Term Possible on Fundamentals

• Potential for Lower Costs With Students

• Leverage Our Internal Resources

• Network of Researchers/Relationships

• Norwegian Institutes Increasingly Involved

Acknowledgements Acknowledgements

• ConocoPhillips Management

• Reservoir Recovery Mechanisms Staff– Past and Present

• U. of Bergen, Rogaland University

• Numerous COP Employees

The EndThe End

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