Anthropogenic CO₂ for Enhanced Oil Recovery: An Under-Utilized Resource for Greener Fuels

Abstract

World oil basins have the potential to recover over 1 trillion barrels of oil with enhanced oil recovery (EOR) using CO₂ from known and undiscovered oil in place (Godec et al, 2011). The ability to recover these oil reserves is limited by the availability of CO₂ resources. At 1.5 barrels of oil produced/metric ton of CO₂, the required CO₂ for EOR in all basins would be over 700 billion metric tons. Assuming the recovery took 100 years, the market demand for CO₂ could be over 7 billion metric tons/year. Atmospheric anthropogenic CO₂ releases in 2011 were ~31.3 billion metric tons; stationary electricity and industrial sources of CO₂ totaled ~14.5 billion metric tons (IEA, 2013). This suggests that there is likely enough man-made CO₂ available for potential world demand. CO₂ used in EOR is typically of geologic origin, of relatively high purity (~95% CO₂), and sells for between 2% to 3% of the value of a barrel of recovered oil per 1000 ft3 of gas (Permian Basin of west Texas). This equates to ~$32US to ~$48US per delivered metric ton (crude oil valued at $85US/barrel). Most methods of CO₂ capture from industrial sources cost over $50US per metric ton prior to compression and transport; compression and pipeline costs represent an additional cost of ~$15US per ton. Lower cost methods of CO₂ capture are needed for widespread use of CO₂ in EOR. CO₂ is commonly recognized to have the potential to recover an additional 15 to 20% of original oil in place, with oil production ranging from 1–3 barrels/metric ton of CO₂ lost to the reservoir. The long-term oil recovery potential of CO₂ is not well understood because of the lack of low cost CO₂ for flooding. CO₂ flooding is common in the Permian Basin due to the nearby geologic CO₂ sources. CO₂ is typically only effective in recovering medium and light crude oil. Medium and light oil produced at rates of less than 2.0 to 2.8 barrels respectively; per metric tons lost are likely CO₂ negative. CO₂ negative is when it takes more CO₂ to recover the oil than it will produce upon combustion. Negativity can be calculated based upon oil density, carbon content, conversion of carbon to CO₂, and the comparison of combustion produced CO₂ to lost CO₂. Crude oil is variable but a general understanding of the negativity of EOR with CO₂ can be developed. The use of man-made CO₂ for oil recovery offers the potential for greener fuels.

AAPG Datapages/Search and Discovery Article #90216 ©2015 AAPG Annual Convention and Exhibition, Denver, CO., May 31 - June 3, 2015