The department said once the field is depleted, it could then be used to store carbon dioxide, instead of releasing the gas into the atmosphere and exacerbate global warming.
The carbon dioxide injected into the oil field would act much like the C02 in a soda can when it fizzes and forces out liquid. In a field, the CO2 would thin the crude left behind, pressurize it, and move the oil to producing wells.
The project, proposed by the University of Alabama in Birmingham, calls for flooding the state's Cintronelle oil field in Mobile County with CO2. The Cintronelle field is the state's largest oil producing field.
The department chose the field for the project because of its uniform geological structure and for the fact that the field has already been flooded with water to recover oil.
But with so-called CO2 flooding, about 20 percent more of the oil originally in a reservoir can be recovered. At the Cintronelle field, the department said an extra 64 million barrels might be squeezed out using the technique.
When the all economically-recoverable oil is removed, the reservoir and adjacent formations can then become storage sites for C02 produced from the coal and natural gas burned at nearby power plants.
Southern Company one of the country's biggest electricity generators, is looking into using such reservoirs for CO2 storage.
Using C02 for enhanced oil recovery now produces about 237,000 barrels of crude a day, equal to almost 5 percent of total US oil output.
However, CO2 flooding is very expensive without a readily available source of gas. That's why about half the world's CO2 flooding takes place in the Permian Basin oil reservoirs in West Texas and New Mexico, which are close to some of the biggest natural CO2 sources.
But the department said using the technology at current fields could increase C02-enhanced oil production to 500,000 barrels a day by 2012 and to 2 million barrels by 2020.
Story by Tom Doggett
http://www.planetark.com/dailynewsstory.cfm/newsid/37992/story.htm