Research shows that for every barrel of crude oil produced in the United States, two barrels of oil are left in the ground, inaccessible by traditional primary or secondary production methods. Enhanced oil recovery (EOR) or tertiary production techniques can be used to restore formation pressure and improve oil displacement or fluid flow in reservoirs to produce the stranded reserves. The Department of Energy has determined that EOR using carbon dioxide (CO2) flooding could add approximately 89 billion barrels to the nation’s recoverable oil resources.
Ameriwest Energy is leveraging extensive EOR expertise to reinvigorate production in mature oil fields. The company is preparing for a full field CO2 flood program to recover additional barrels of oil from its South Glenrock “C” project, located in the Powder River basin of Wyoming. Ameriwest Energy has engaged NITEC LLC, a reservoir engineering firm with seasoned experience in CO2 injection projects.
Crude oil production can include up to three phases. During the primary recovery phase, the natural pressure of the reservoir or gravity drives oil into the wellbore, combined with artificial lift techniques such as pumps which bring the oil to the surface. Only 10% of a reservoir's original oil in place is typically produced during primary recovery. The secondary recovery techniques add to the field's productive life by injecting water or gas to displace oil and drive it to a production wellbore, resulting in the recovery of 20 to 40% of the original oil in place. With much of the easy-to-produce oil already recovered from U.S. oil fields, producers are employing tertiary or enhanced oil recovery techniques including gas injection, which offer prospects for producing 30 to 60% or more of the reservoir's original oil in place. (Percentages released by the US Department of Energy)
CO2 gas injection accounts for nearly 50% of EOR production in the U.S. and now accounts for approximately 4% of domestic oil production, according to the National Energy Technology Laboratory. This technique was first tried in 1972 in Scurry County, Texas, and has been used successfully throughout the Permian Basin of West Texas and eastern New Mexico, and is now being pursued in Wyoming, Utah, Kansas, Mississippi, Oklahoma, Colorado, Montana, Alaska, Pennsylvania and Alberta, Canada.
