1 rpsea.org

Characterization of Potential Sites for Near Miscible CO2 Applications to Improve Oil Recovery in Arbuckle Reservoirs

Jyun-Syung TsauPresented by Mark BallardTertiary Oil Recovery ProgramUniversity of Kansas

Midland CO2 ConferenceDecember 6, 2012Midland, Texas

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Overview

Project was administered through RPSEA to address the technology challenges of CO2 near miscible application

Phase I was completed in October, 2010

Phase II is in progress

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Overview

Arbuckle represents a significant resource for improved oil recovery

Many Kansas reservoirs operated by small producers are not candidates for CO2 miscible application

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CO2 for Enhanced Oil Recovery

Immiscible

Near miscible

Miscible

SwellingViscosity reduction

SwellingViscosity reduction

Extraction

Miscibility

Immiscible

Miscible

Near miscible

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Research Tasks

o Phase I • Phase behavior study

Hydrocarbon characterization

MMP measurement

Swelling/Extraction test• Core flow tests

o Phase II• Reservoir characterization • Engineering tests• Reservoir simulation• Pattern design

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MMP Measurement

T = 110oF

MMP0.8MMP

High displacement efficiency

(Ly H. Bui, 2010)

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Typical Swelling/extraction Results

Extraction

110 ºF

Swelling

Swelling and Extraction(Ly H. Bui, 2010)

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Effect of CO2 on Oil Viscosity

Viscosity reduction

(Ly H. Bui, 2010)

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Recovery Efficiency

Residual oil mobilization

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Summary

Laboratory results shows a favorable mechanism to improve oil recovery with CO2 injection at near miscible condition

Swelling, extraction/vaporization of light hydrocarbon constituents into the CO2 rich vapor phase & reduction of oil viscosity are the primary mechanisms for the near miscible displacement process

CO2 injection mobilizes more than 50% of the water-flood residual oil in the near miscible range

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Project Location

Ogallah unitTrego county, Kansas

Source: Kansas Geological Survey

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Characteristics of Arbuckle

Arbuckle reservoir typesArbuckle final shut-in pressure

Abundant fracturing of strata

Karst control

Lithofacies control

E.K. Franseen, A. P. Byrnes, J.R. Cansler, 2004 , Current Research in Earth Sciences, Bulletin 250, part 2

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Challenges

Reservoir description

Mature oil field

Vintage well logs

Limited porosity logs

Undocumented reserve• Residual oil saturation

Improved characterization

Single well tracer test

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Improved Characterization Ogallah Field

MicrologsMicrologs

Cored WellsCored Wells

Shale

Do Top

SS Top

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Porosity Estimation Workflow

Wackesto

ne

Packesto

neGrains

tone

(Lucia F.J., 2007)

(Woan Jing Teh, 2011)

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Porosity Verification

“ Improved Predictions of Porosity from Microresistivity Logs in a Mature Field through Incorporation of Pore Typing,” SPE paper 149506 presented in SPE Eastern Regional Meeting, Columbus, Ohio, August 17-19, 2011.

(WoanJing Teh, 2011)

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Permeability Estimation

“ Improved Reservoir Characterization using Petrophysical Classifiers within Electorfacies,” SPE paper 154341 presented in SPE Improved Oil Recovery Symposium, Tulsa, Oklahoma, April 14-18, 2012.

(Woan Jing Teh, 2012)

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Reservoir Model

“Improved Reservoir Characterization and Simulation of a Mature Field Using an Integrated Approach”Woan Jing Teh MS Thesis, University of Kansas, 2012

(Woan Jing Teh, 2011)

Porosity Permeability Water oil contact

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Lease production

Lease 1 Lease 3

Lease 4 Lease 7

Improved Reservoir Characterization and Simulation of a Mature Field Using an Integrated ApproachWoan Jing Teh MS Thesis, University of Kansas, 2012

(Woan Jing Teh, 2011)

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Summary

Leverage existing logs and core data

Develop a workflow leading from vintage micro-resistivity logs and core analysis to

PorosityPermeability

Create CMG computer reservoir models to history-match production

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Moving Forward

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Engineering Tests

Pressure Build‐Up

Pressure  Interference

Single‐Well  Tracer

Interwell Tracer

Descriptionof the

Arbuckle

Individual Well Multiple Well

Pressur e

TracerTwo stageSingle‐Well 

Tracer

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Single Well Tracer (SWT) Test

Determine

•

Remaining oil saturation

Procedure

•Inject partitioning tracer into selected well•Shut in well & allow hydrolysis reaction•Produce the well•Sample produced fluid & draw tracer 

curves

Ester Injection Produced back

Chemical Tracers, Inc.

Sw

Sor

Shut inEtAc + H2 O EtOH + HAc

Ester Injection

Production back

Chemical Tracers, Inc.

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Two‐stage SWT test/CO2 Injection

Determine

Difference of remaining oil 

saturation between two SWT tests

Procedure

1st

single well tracer test

Injection of 50 tons of CO2 

at 

near miscible condition

Followed by similar amount 

of formation brine

2nd

single well tracer test

Ester Injection Produced back

CO2Brine CO2 = 0.18H= 30 ft

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Candidate Wells

o Several operators have shown interests

o Seven wells are to be evaluated

o Oil properties, well and reservoir conditions are to be considered for evaluation

o Effectiveness of CO2 injection at near miscible condition is to be evaluated

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Summary

Identified potential sites for applying CO2 injection at near miscible conditions in Kansas

Applied an improved method to estimate porosity and permeability from well logs, which will lead to a better reservoir description

Aid understanding of the reservoir and remaining reserve in Arbuckle

Increase domestic production for small producers and the resource base for CO2 flooding and sequestration

Serve as a useful guide for oil operators considering oil recovery by CO2 injection

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Acknowledgements

o Project Team• Phase II

Mark Ballard

Evan Franseen

Jenn-Tai Liang

Kourosh Reza Maleki (GRA)

Jyun-Syung Tsau

Paul Willhite• Phase I

Ly Huong Bui (GRA)

Woan Jing Teh (GRA)

o Others• Martha Cather• Bob Kiker• Chandra Nautiyal• Scott Ramskill• Charlotte Schroeder• Dana Wreath

Carmen Schmitt Inc.

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Extra Material

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Ogallah

Field

Active producerTACored well

SWD

SWD

Producer

TA

Arbuckle Producer

Arbuckle TA

1255 12501325

1037

1264

1225

Average Shut in pressure ~ 1226 psi (Near Miscible)