The US Department of Energy (DOE) claims that technological advances, economic improvements, and environmental needs are pushing developments in a proven method for enhancing oil recovery – carbon dioxide (CO2) flooding.

A watershed project in Kansas funded by DOE seeks to demonstrate that this technology’s time has come, while leveraging energy security, energy efficiency, and environmental benefits in several ways. The payoff could be hundreds of millions of barrels of oil in Kansas that otherwise might never be produced, according to the DOE.

Until now, enhanced oil recovery (EOR) using CO2 has not been feasible in Kansas because the largest natural sources of CO2 in the US are hundreds of miles away. The resulting high transportation costs would doom the economic feasibility of any CO2 flood. Currently all but a handful of CO2 floods in the US are in the Permian basin of West Texas and New Mexico, not far from large deposits of CO2.

The Kansas project takes a different approach, capitalising on the benefits of what amounts to a unique, scalable model for linked energy systems, according to the DOE.

This approach entails using waste heat from a 15-megawatt natural-gas-fired turbine generator to provide thermal energy for a 25 million gallon-per-year corn ethanol plant. The project then recovers some of CO2 generated by fermentation for corn ethanol production and uses it for a CO2 EOR flood in the Hall-Gurney field in central Kansas.

The Hall-Gurney flood represents a couple of firsts – the first CO2 flood in Kansas, and the first time waste CO2 from an ethanol plant has been used for enhanced oil recovery.

Both are significant achievements. If the project proves feasible, it could open the door for CO2 floods throughout Kansas and for other parts of the world where ethanol and oil production co-exist.

The potential added incremental oil recovered from such an effort could total as much as 600 million barrels of oil in Kansas alone. As many as 6,000 mature oilfields in the state could be saved from abandonment – not to mention the thousands of jobs created from implementing these projects.

CO2 EOR projects are proliferating in the US as operating costs of these projects and CO2 prices have dropped sharply in recent years. Given the immense volumes of bypassed oil in thousands of mature or declining oilfields, and expectations for persistently high oil prices, CO2 EOR projects seem likely to continue to expand.

An enhanced oil recovery project using industrial waste CO2 also "closes the carbon loop" by injecting underground CO2 that otherwise would be vented to the atmosphere. Such carbon sequestration efforts are the subject of intense research and government scrutiny worldwide amid growing concerns over the role that human-created CO2 emissions play in global climate change.

Oil production from the Hall-Gurney CO2 flood started up in May 2004, following six months of CO2 injection. The pilot project is using only 10% of the CO2 stream from the ethanol plant at Russell, Kansas, from which the gas is trucked seven miles to the field site.

One such ethanol plant could supply a small oilfield, capable of producing 5 million barrels of oil and sequestering 1.5 million tons of CO2, for 20 years, according to the DOE. If CO2 flooding were implemented across the entire Hall-Gurney oilfield, it would require CO2 waste gas volumes from the equivalent of five such ethanol plants.

Combined, the benefits from integrating power, ethanol production, enhanced oil recovery, and CO2 sequestration could total $88 million over 10 years, if all of the plant’s CO2 were used, the DOE claims.

The Kansas project is managed by the National Energy Technology Laboratory in partnership with the Kansas Geological Society at the University of Kansas in Lawrence, Kinder Morgan CO2 Co LP (Houston), Murfin Drilling Co. (Wichita, Kansas), MV Energy (Princeton, N.J.), ICM Inc. (Colwich, Kansas), and the Kansas Department of Commerce.