November 15, 2005

Oil Fields Could Help Cut Co2 Emissions

WASHINGTON - A technology for capturing carbon dioxide in oil fields could have the same impact on the environment as removing millions of cars from roads, U.S. energy officials said on Tuesday.

Five million tons of Co2, a gas linked to global warming, was successfully stored in a Canadian oilfield while doubling the field's crude oil recovery rate, the Energy Department said.

The promising technology in the multi-national project could be used to capture and store carbon dioxide in geologic formations, U.S. officials said.

"By applying this technique to the oil fields of Western Canada, we would see billions of additional barrels of oil and a reduction in Co2 emissions equivalent to pulling more than 200 million cars off the road for a year," U.S. Energy Secretary Sam Bodman said in a statement.

The project injected carbon dioxide into the Weyburn oilfield in Saskatchewan, increasing underground pressure to boost crude oil production by 10,000 barrels per day. The technique, known as enhanced oil recovery, is used by many oil companies to keep aging fields productive but typically uses more costly carbon dioxide from naturally occurring reservoirs.

Carbon dioxide used at Weyburn was piped from the Great Plains Synfuels Plant near Beulah, North Dakota. The carbon is a byproduct of the plant's coal gasification process and would otherwise be released into the atmosphere, the Energy Department said.

The United States is the biggest emitter of carbon dioxide, one of several greenhouse gases blamed for melting glaciers and rising sea levels. Legislation to require cuts in U.S. emissions have repeatedly failed in Congress.

Primary oil recovery uses natural underground pressure to bring oil to the surface but typically produces only 10 percent of a field's potential. Secondary recovery techniques inject water to flood a field and force the oil upward, increasing recovery by 20-40 percent.

Enhanced oil recovery, the technique used at Weyburn, has the potential to increase a field's oil recovery up to 60 percent, the Energy Department said.

The Weyburn project is led by Canada's Petroleum Technology Research Center in Regina and also involves EnCana Corp, Japan and the European Commission. It is part of an international climate change initiative trying to find ways to capture and store carbon dioxide.