EORI Library

Dr. Eric Robertson provides a retrospective analysis of the Enhanced Oil Recovery Institute’s (EORI) collaborative work in Wyoming since 2004, focusing on CO₂ enhanced oil recovery projects within the state.

CO₂ - EOR technology has been instrumental in producing significant volumes of oil from four key fields: Beaver Creek, Big Sand Draw, Grieve, and Salt Creek. The analysis of each field is accompanied by charts that illustrate the dramatic benefits of CO₂ - EOR technology.

As of April 2024, 67 million barrels of incremental oil have been produced from these fields, providing $558 million in tax revenue to the state, and will continue to grow as these CO₂ - EOR fields continue to produce.

Eric Robertson, PhD, PE, is the Principal Engineer at Robertson Solutions, LLC.

On January 8th, 2025 EORI held Enhanced Oil Recovery Insights featuring Robert Downey. The event topic was "Discover CycleStim."

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A brief discussion of the first CO2-EOR project in the Minnelusa Formation and how an improved process for mapping reservoir flow units can help optimize oil recovery.

The Enhanced Oil Recovery Institute (EORI) has published a new bulletin titled A Review of the Wyoming Pipeline Corridor Initiative: Facilitating CO₂-EOR in Wyoming. This publication, authored by Brian Jeffries, EORI’s Commercial Pipeline Advisor, provides a detailed review and recounting of the history and development of the Wyoming Pipeline Corridor Initiative (WPCI).

The WPCI studied available space in existing pipeline corridors on Bureau of Land Management (BLM) lands in Wyoming to facilitate the future development of pipeline transportation of carbon dioxide (CO₂) for enhanced oil recovery (EOR) in the state. The Wyoming Pipeline Corridor Initiative facilitates growth in both oil and gas production and in carbon capture, utilization, and storage (CCUS) and reduces costly and timely federal regulatory challenges.

Significant oil reserves remain in many Minnelusa fields and detailed reservoir characterization is a key to developing optimal EOR strategies. Sequence stratigraphic principles have shown great promise in being able to adequately map flow units within these complex reservoirs and help indicate ways to improve production.  Not only can sequence stratigraphic mapping in the Minnelusa help improve production in existing fields, but together with modern 3D seismic data it may further improve EOR efforts as well as helping to locate new fields.

On November 13th, 2024 EORI held Enhanced Oil Recovery Insights featuring Tristan Houser, Vice President of Operations, Polymer Technologies and Troy Skitt – Operations Engineer, Merit Energy. The event topic was "Using Polymers for Water Control and Casing Leak Repairs."

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On August 14th, 2024 EORI held Enhanced Oil Recovery Insights featuring WOGCC Supervisor Tom Kropatsch.

Tom Kropatsch has been with the Wyoming Oil and Gas Conservation Commission (WOGCC) since 2010 and served as a Natural Resources Analyst, Natural Resources Supervisor, Deputy Supervisor, Interim Supervisor and since 2021 as the State Oil and Gas Supervisor. During his tenure at the WOGCC, Tom has been responsible for the implementation of the agency’s environmental programs such as baseline groundwater quality; remediation and disposal of exploration and production generated wastes; recycling, reuse, and disposal of flow back and produced water; spill and incident response; pit and seismic permitting; and the bonding program.

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A reprint of Formation Water Resistivities originally compiled by Don Cardinal (1984) is now available on the EORI website. This publication is a valuable resource for establishing Rw values necessary for calculating oil and water saturations from wireline logs.

A reprint of Formation Water Resistivities originally compiled by Don Cardinal (1984) is now available on the EORI website. This publication is a valuable resource for establishing Rw values necessary for calculating oil and water saturations from wireline logs. Data are compiled by basin and include: well name and location, formation, depth, source of the water, Shut-in-Pressure, and measured water resistivity.

CO2– EOR has been an important part of the oil industry for well over 50 years. The firstCO2 flood in Wyoming (1986) continues today at Lost Soldier/Wertz Fields (Baroil). Since 1986 incremental oil production from CO2- EOR is approximately 150 million barrels with severance tax revenue to the State of over $400 million ($50/bbl oil price).

The CO2 used to recover oil is part of a “closed-loop-system”. The CO2 is injected, separated from the produced oil, recycled, and reinjected. Through the life of the project, all CO2 injected (purchased and recycled) is stored in the reservoir.

CO2 is an expensive commodity for EOR with an approximate cost of ~ 2% of oil price (WTI)/MCF. Some floods in Wyoming have purchased well over 200 MMCF/Day - over $300,000/day just for CO2.

A successful reservoir model requires the right kinds of data as well as accurate data.

3D reservoir modeling is useful for petroleum reservoir production forecasting and for developing a methodology to optimize recovery.  Reservoir modeling requires a commitment to assimilating accurate information in the proper format and this document outlines the requirements, descriptions and importance of key data.

On September 12^th, Scott Ellingson, a contract Petroleum Geologist with the Enhanced Oil Recovery Institute, and John Frederick, a consulting Geophysicist, presented Alpha Field - Exploitation and reservoir characterization of the Minnelusa C Sand using sequence stratigraphy and modern 3-D seismic, Powder River Basin, Wyoming.  Mr. Ellingson and Mr. Frederick summarized their work, concluding that calculations for the original oil in place at Alpha Field has increased to 19.1 MMBO and that the new data indicate two proved undeveloped locations. (PUDs). Furthermore, their work enabled them to predict rates of deliverability for these two new potential drill sites.

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New thoughts and queries about the Muddy Formation in the Powder River Basin focusing on ways that could improve production.

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The rock layers surrounding Alcova Lake are not only breathtaking to see, they are also windows to a portion of the earth’s history. This guidebook hopes to introduce anyone interested to a brief explanation about what the geology is revealing.

EORI shares this guidebook as part of its commitment to facilitating technology transfer through publications and oral presentations.

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At Rozet Field, the lack of abundant core analyses or modern logs necessitates the adoption of more assumptions than usual in order to estimate OOIP and remaining recoverable reserves. Two different methods for calculating the recovery efficiency of the waterflood were applied withinnine 5-spot patterns resulting in maximum rates of 40% and 30% respectively. Average recovery factors in the combined 5-spot patterns are 27.5% and 24.4% respectively. Both values indicate the waterflood is probably not as effective as it could have been when compared to similar fields producing from the Muddy Formation.

The calculated OOIP for the Muddy Formation at Rozet is about 74.7 million barrels, of which a little over 19 million barrels have been recovered. The recovery factor for the field is then about 25.5%. If a 40% recovery factor is achievable with an efficient waterflood, then the remaining recoverable oil reserves from the Muddy Formation at Rozet Field are approximately 10.8 million barrels. This magnitude of a target should warrant further investment in improved and enhanced recovery methods there.

At nearby Windmill Field, secondary recovery has yet to be implemented in the Muddy reservoir. Wireline log suites containing porosity logs in this field enable more confidence in the geologic mapping and OOIP calculations than at Rozet. Cumulative oil production there is 677,735 barrels, resulting in a recovery factor of about 14.8%. Assuming the clay content does not vary significantly from that observed at the adjacent Rozet Field, a well-designed waterflood should be effective at increasing production in Windmill Field. If a recovery factor of 40% could be achieved by implementing secondary recovery efforts there, it could result in the production of an additional 1,157,465 barrels of oil.

• Nine different reservoirs in seven fields have employed fieldwide CO2 EOR in Wyoming.
• Between 2010 and 2020, incremental oil recovery from the nine CO2 EOR projects accounted for over 10% of Wyoming’s total oil production.
• Wyoming is not constrained by CO2 sources that can be used for EOR projects.
• Wyoming is also not constrained by fields potentially amenable to CO2 EOR.
• Wyoming is not constrained by pipeline capacity for additional CO2 transport, but is hampered by the existing pipeline system not reaching many of the best-potential fields, especially in the Big Horn Basin.
• The most successful CO2 floods resulted from proper reservoir characterization and associated optimized project design. Wyoming has seen incremental oil recovery from individual CO2 EOR projects as high as 18% of OOIP and volumes as high as 30 million barrels.
• Where net CO2 efficiencies could be calculated, CO2 efficiency is as low as 6 Mcf/bbl of incremental oil recovered, which compares very favorably to other successful projects around the world.