Enhanced Oil Recovery (EOR)

Already discovered oil fields in the U.S., not including oil shale or tar sands, had an estimated 582 billion barrels of original oil in place.  We have produced or proven about 208 billion barrels from those fields, which leaves about 374 billion barrels of oil that is or will be "stranded" in known deposits that have already been drilled.  Current EOR technologies would provide access to an estimated 110 billion barrels of that oil and future EOR technologies could provide access to even more. 

Primary recovery techniques, including natural pressure, gravity, and pumps, generally only produce about 10% of the oil available in any given deposit.  Secondary recovery techniques such as water flooding or reinjecting the natural gas also produced in order to maintain pressure produce another 10% - 30% of the oil, leaving 60% - 80% of the original oil still in the reservoir.  Tertiary techniques, also known as enhanced oil recovery, provide access to significantly more of the original oil in place. 

Current EOR technology includes thermal recovery, gas injection, and chemical injection.  Thermal recovery has mainly been used for heavy oil resources thus far.  CO2 injection is the predominant method for lighter oils.  Research from the 1990's indicated that using CO2 injection in conjunction with horizontal wells and CO2 miscibility and mobility control agents significantly increases the amount of economically recoverable oil.  The best method(s) to use depends on the specific geological and other characteristics of an given reservoir.

Ongoing research into new advanced recovery technologies, such as microbial processes, seismic vibrations, and microwave, electric, and acoustic heating, in conjunction with current EOR technology, could make 65% or more of the original oil in place recoverable.

Additional EOR Resources

EOR in Williston Basin

Unconventional Fuels Task Force

NPR's National Strategic Unconventional Resource Model

"From Reservoir to Refinery" and Other Educational Posters

CO2 Enhanced Oil Recovery

Carbon Management for Strategic Unconventional Resources

DOE EOR R&D Program

DOE Energy Techline - 3/3/06

DOE Energy Techline - 1/3/05

DOE Carbon Sequestration Research

DOE Techlines on carbon sequestration

Undeveloped domestic oil resources: A foundation for increasing oil production

CO2-EOR Fact Sheet

CO2 EOR Technology

Exploration and Production Technologies

EOR Process Drawings

Game Changer Improvements in EOR

Stranded Oil in the Residual Zone