t

QUARTERLY TECHNICAL PROGRESS REPORT GREEN RIVER FORMATION WATER FLOOD DEMONSTRATION PROJECT

UINTA BASIN, UTAH DE-FC22-93BC14958

Inland Production Company Denver, Colorado

Award. Date: October 21, 1992 Anticipated Completion: March 31, 1995

Program Manager: Bill I. Pennington, Lomax Exploration Company/Inland Resources

Principal Investigators: John D. Lomax, Lomax Exploration Company/Inland Resources Dennis L. Nielson, Earth Sciences Research Institute, University of Utah Milind D. Deo, Department of Chemical and Fuels Engineering, University of Utah

Technical Project Officer: Edith Allison, Bartlesville Project Office

Reporting Period: October 1, 1995 - December 31 1995

OBJECTIVE

The objective of this project was to apply the successful water flood technologies developed for the Monument Butte unit to other units in the vicinity. It was discovered that the unit boundaries were artificial and that an approach that considered reservoirs spanning several units was required. .A comprehensive geostatistical da ta management and integration activity for a 12-section area around the Monument Butte unit is now underway.

SUMMARY OF TECHNICAL PROGRESS

Field Activities The cumulative productions as of December 31, 1995 for some of the project wells and wells

drilled for unit expansions are summarized below.

M o n u m e n t B u t t e Unit (Un i t Wells) Well Number Oil (BBL) Gas (MCF) Water (BBL) 10- 34 16,364 22,i89 4,367 9-34 20,587 15,623 3,580 7-34 11,088 16,402 671 2A-35 12,372 4,109 234 Unit 1,089,871 2,229,901 186,025

-. .. .

DISCLAIMER

Portions of this document may be illegible in electronic image products. Images are produced from the best available original document.

Monument Butte Unit (Unit Expansion Wells) \Vest Expansion \Vel1 Number Oil (BBL) Gas (MCF) Water (BBL) 6-34 3,835 13,943 2,593 5-34 14,951 20,784 448 3-34 964 0 575 East Expansion Well Number Oil (BBL) Gas (MCF) Water (BBL) 3--36 2,111 1,797 170 10-36 11,578 2,220 1,216 14-36 14,394 25,596 1,535 15-36 2,597 152 4,657 16- 36R 8,507 7,291 922 South East Expansion Well Number Oil (BBL) Gas (MCF) Water (BBL) 4- 1 1,403 0 631 5- 1 3,541 0 2,688 8-2 4,131 0 344 North East Expansion \Vel1 Number Oil (BBL) Gas (MCF) Water (BBL) 11-25 5,482 0 455 12-25 1,120 0 306 13- 25 6,557 4,320 288 14-25 8,349 3,705 280 15- 25 27,270 9,959 2,002 16-26 5,149 1,934 380

\Vel1 Number Oil (BBL) Gas (MCF) Water (BBL) 5-33 4,972 19,868 652 Unit 292,164 1,387,915 17,612

Travis Unit

Boundary Unit Well Number Oil (BBL) Gas (MCF) Water (BBL) 12-21 2,495 2,894 4,413 10-21 7,778 3,718 1,401 Unit 200,883 621,271 26,127

Geostatistical Modeling and Reservoir Simulation The methodoIogy of generating geostatistical reservoir images was outlined in the previous

quarterly report. In order to test the sand connectivities, a 12-section area around the Monu- ment Butte unit was modeled. The area consisted of sections 25, 26, 27, 28, 33, 34, 35, 36 in township/range 8S/16E (Duchesne County) and sections 1, 2, 3 and 4 in township/range 9S/16E. Five different sands have been targeted for analysis and the analysis using D l sand data has been completed. Log-data at two feet resolution was digitized and used as the base data set a t well loca- tions. Density porosities were used for porosities as a function of depth and water saturations were determined using a dual-porosi ty model. Thus, porosities and water saturations were available a t well locations as functions of depth. Permeabilities were determined using a porosity-permeability cross-plot. Vertical variograms were generated at each well location and were combined with the

two-dimensional x-y variograms. The vertical domain was normalized and divided into 100 layers for geostatistical simulations. The 100 layers were later upscaled to 5 or 10 layers using single-phase upscaling techniques for reservoir simulation purposes. Thus, a reservoir image that accounted for all of the available data in the 12-section area was generated. This reservoir characterization scheme did not use any adjustable parameters.

Results of reservoir simulation using one of the generated realizations are discussed below. In D1-sands, the Monument Butte unit contained 10.3 MMstb of oil compared to a total of about 58 MMstb in the entire 12-section area. The average oil saturation in the unit was about 76% compared to 74% in the total area. The initial reservoir pressure was assumed to be 2500 psia based on a gradient of about 0.5 psi/ft. When the water flood was initiated in the unit in September of 1987, the average pressure in the unit had drpped to about 1400 psia compared to an average pressure of 2160 psia for the entire region. These numbers provide the extent of drawdown that the unit as a whole created with respect t o the surrounding reservoir. The cumulative production from the unit was about 370 Mstb or about 3.5% of the original oil in place. The total primary production for the unit was about 420 Mstb and about two-third (281) to three-fourth (315) of this production is believed to be from the D sands. Thus, the model overpredicts primary production. The model results are still reasonably close to the field results considering that there are no adjustable parameters in the model. At the end of 1995, the model predicts a production of about 520 Mstb. The total production from the unit as of December 1995 was about 1.1 MMstb. The the D-sand contribution is believed to be between 700 Mstb to 800 Mstb. Thus, the model underpredicts water flood performance significantly. The model does not take into account hydraulic fractures. The results obtained thus far indicate that it is very important to consider the effect of hydraulic fractures on production. A material balance on water does indicate that most of the water injected into the unit stays in the unit. More simulations are being conducted on different geostatistical realizations t o assess the variability in production which could be attributed to representation of reservoir heterogeneity.

TECHNOLOGY TRANSFER

A paper being is presented at the SPE-DOE Symposium on Improved Oil Recovery to be held i n Tulsa, Oklahoma in April, 1996. The results of comprehensive geologic characterization and reservoir simulations will be presented in an invited lecture a t the AAPG Meeting in Billings, Montana in July, 1996.

PUBLICATIONS

“Water Flood Project in the Monument Butte Field, Uinta Basin,” presented by John D. Lomax, Annual meeting of the Interstate Oil and Gas Compact Commission, December 6-8, 1992, Salt Lake City, U t a h .

“Water Flood Project in the Uinta Basin,” presented by Milind D. Deo, Monthly meeting of the Salt Lake section of the Society of Petroleum Engineers, February 16, 1993, Salt Lake City, Utah.

“Potential of Water Flooding in the Uinta Basin,”presented by Milind D. Deo, Monthly meeting of t h e Uinta Basin section of the Society of Petroleum Engineers, March 25, 1993, Vernal, Utah.

“Green River Formation Water Flood Demonstration Project Showing the Development of New Re- serves i n the Uinta Basin” presented by John D. Lomax, meeting of the Workshop for Independent Oil & Gas Producers in the Appalachian & Illinois Basins, June 4, 1993, Lexington, Kentucky.

4 , *

“Green River Formation Water Flood Demonstration Project Showing the Development of New Reserves in the Uinta Basin,” presented by John D. Lomax, meeting of the Subcommittee on Renewable Energy, Energy Efficiency and Competitiveness of the U.S. Senate Committee on Energy and Natural Resources held on November 30, 1993, Roswell, New Mexico.

“Monument Butte Case Study, Demonstration of a Successful Waterflood in a Fluvial Deltaic Reservoir”, Deo, M. D., Sarkar, A., Nielson, D.L. and Lomax, J.D. and Pennington, B.I., PE 27749, Paper presented a t the Improved Oil Recovery Symposium of the SPE and the U.S. DOE in Tulsa, Oklahoma, April 17-20, 1994.

“Green River Formation Water Flood Demonstration Project”, Yearly Report t o be published by the U.S. DOE, 89 pp.

“Description and Performance of a Lacustrine Fractured Reservoir”, Deo, M. D., Neer L. A., Whitney, E. M., Nielson, D. L., Lomax, J. D. and Pennington B. I., SPE 28938, Paper to be presented in the Poster Session of the Annual Fall Meeting of the Society of Petroleum Engineers.

“Solids Precipitation in Reservoirs Due to Nonisothermal Injections”, Deo, M. D., SPE 28967, Paper presented at the SPE International Symposium on Oil Field Chemistry, San Antonio, Texas, February, 1995.

“Effect of Reservoir Connectivity on Primary and Secondary Recovery”, Pawar, R. J., Deo, M. D. and Dyer, J., SPE 35414, Paper to be presented at the SPE/DOE Improved Oil Recovery Symposium in Tulsa, Oklahoma, April, 1996.

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer- ence herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom- mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.