EORI Library
Find publications about Enhanced Oil Recovery (EOR).

EORI Library

As a part of our implementing our mission, we have conducted and facilitated studies, presentations and other documents on the topic of Enhanced Oil Recovery (EOR). These documents are broken into subcategories to help you find the information pertinent to each topic. 


The law and economics of CO2 as a pollutant and commodity
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  • We think of CO2 as the greenhouse gas (GHG) causing global warming.
  • The Stern Report and the several IPCC (Intergovernmental Panel on Climate Change) reports are gaining acceptance.
  • In its most recent report (AR4 Synthesis Report November 17, 2007) the IPCC has written: Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.
  • The report goes further to say: Most of the observed increase in globallyaveraged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations.
  • The Supreme Court on April 2, 2007 in a 5 to 4 decision decided that CO2 was a pollutant and the EPA could regulate auto emissions of the GHG (Chemical & Engineering News, April 3, 2007).

Cardinal Water Resistivities in Wyoming Basins Booklet
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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.

EORI CO2 EOR Fact Sheets 2024
 2.9 MB

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.

EORI Data Requirements for Dynamic Reservoir Simulation Modeling
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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.

EORI Insights Event: Alpha Field Exploitation and Characterization
 4.19 MB

On September 12th, 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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EORI Insights Event: Thoughts on Regional Geology Muddy Formation
 19.47 MB

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

View Video Presentation

Guidebook to the Geology of Lake Alcova, Natrona County, Wyoming
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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.

View Associated High Resolution Maps

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.

CO2 Enhanced Oil Recovery in Wyoming: 2020 Update
 2.28 MB

• 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.

The results of EORI’s sponsored test of Viper Drill’s ultrashort radius (USR) drilling technology could be a sound investment for Wyoming operators.

Ultrashort radius drilling technology was successfully tested in two wells (an injector and a producer) at Thompson Creek Field in northeastern Wyoming that were experiencing problems due to near-wellbore formation damage.  Both wells exhibited marked improvement in performance after the drilling of four short (<30’ long) USR laterals from each borehole, indicating that this method should be considered in other wells throughout the state that are experiencing similar problems.

Reservoir characterization and predictive modeling has provided options for enhancing production in a recently discovered trend in the Muddy Formation near Hirsch Field, in northeastern Campbell County, Wyoming. This report outlines the procedures followed to develop a detailed 3-D geologic model of the Muddy Formation in the Hirsch area and provides the results of simulations run on 73 different scenarios for developing the reservoir. This study can serve as a template for operators interested in exploring possible ways to improve production in their own fields.

Application of coalbed methane water to oil recovery by low salinity waterflooding
 1.76 MB

Development and production of coalbed methane involves the production of large volumes of water. The salinities and sodium adsorption ratios of coalbed methane (CBM) water from the Powder River Basin range from 370 to 1,940 ppm and 5.6 to 69 respectively. Surface discharge of CBM water can create serious environmental problems; subsurface injection is generally viewed as economically nonviable. It has been shown that oil recovery from reservoir sandstones can be improved by low salinity waterflooding for salinities ranging up to 5,000 ppm. There may be both technical and regulatory advantages to application of CBM water to oil recovery by waterflooding. Thin section and scanning electron microscope studies of the mineral constituents and distribution of Tensleep and Minnelusa sandstones show they are typically composed of quartz, feldspar, dolomite and anhydrite cements but have very low clay content. The sands contain interstitial dolomite crystals in the size range of up to about 10 microns. Three sandstone cores from the Tensleep formation in Wyoming were tested for tertiary response to injection of CBM water. The cores were first flooded with high salinity Minnelusa formation brine of 38,651 ppm to establish residual oil saturation. Synthetic CBM water of 1,316 ppm was then injected. Tertiary recovery by injection of CBM water ranged from 3 to 9.5% with recoveries for all but one flood being in the range of 5.9 to 9.5%. Previous studies showed that the presence of clay was needed for response to low salinity flooding. As a test of the recovery mechanism, a Tensleep core was preflushed with 15% hydrochloric acid to dissolve the dolomite crystals. The treated core showed no tertiary recovery or pressure response to CBM water.

Produced Water Challenges And Beneficial Use
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Wyoming Oil & Gas Fair / Enhanced Oil Recovery Institute Joint Conference - September 13, 2018

by Shane Horner, Operations Engineer, Merit Energy Company

Power Pump - Electricity & Lifting Costs
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Wyoming Oil & Gas Fair / Enhanced Oil Recovery Institute Joint Conference - September 13, 2018

by Benjamin R. Cook, PhD, Economist/Visiting Professor, Enhanced Oil Recovery Institute & UW College of Business

Wyoming Oil & Gas Fair / Enhanced Oil Recovery Institute Joint Conference - September 13, 2018

by Nick Jones, Sr. Geologist, Enhanced Oil Recovery Institute