A database of Wyoming oil reservoirs is developed to identify candidate reservoirs suitable for miscible or immiscible CO2 flooding, a method that has already proven to be a viable enhanced oil recovery process at Lost Soldier, Wertz, and Salt Creek fields in Wyoming. Based on the CO2 usage of existing CO2-EOR projects in Wyoming and other regions, the initial and total CO2 demands are estimated for the identified reservoirs and grouped by basins. The simple formulas presented in this paper provide a quick estimation of the required initial and total CO2 volumes with specified reservoir parameters. Wyoming has produced about seven billion barrels of oil from more than 1200 oil producing fields. 98% of the oil was produced from the top 400 fields, evaluated in this study, each with a cumulative production exceeding one million barrels of oil. More than 500 oil reservoirs, by passing either miscible or immiscible screening criteria, are identified as potential CO2-EOR candidates. Large fields often have multiple oil producing reservoirs suitable for CO2 flooding. It is estimated that 1.2 to 1.8 billion barrels of additional oil might be recovered by CO2 flooding and up to 20 trillion cubic feet of CO2 could be sequestrated after CO2 EOR in Wyoming's oil basins.

Keywords:
chemical flooding methods, oil reservoir, enhanced recovery, reservoir oil, total co 2, candidate reservoir, recovery factor, estimation, immiscible co 2, basin
Subjects:
Well & Reservoir Surveillance and Monitoring, Reservoir Characterization, Improved and Enhanced Recovery, Formation Evaluation & Management, Reserves Evaluation, Storage Reservoir Engineering, Chemical flooding methods, Miscible methods, Estimates of resource in place, CO2 capture and sequestration
Copyright 2009, Society of Petroleum Engineers
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