Energy companies have injected carbon dioxide into old oil fields in Texas and California for decades, a method that increases underground pressure and mixes with the oil, loosening it from nooks and crannies so it can be removed, The Columbus (Ohio) Dispatch reported Monday.
"It lightens the oil. It fluffs it up," said Larry Wickstrom, Ohio Geological Survey head. "It actually makes it so you can push [the oil] through."
Wickstrom said it hasn't been used in Ohio's oil fields because there is no readily available supply despite the millions of tons of carbon dioxide emitted by coal-fired plants each year. Capturing and transporting the greenhouse gas to the wells is expensive.
Wickstrom said Ohio's first test in 2008 saw a low-yielding well near Canton produce about 58 percent more oil by pumping in 81 tons of carbon dioxide into it, the Dispatch said.
The results inspired a state proposal for more testing by Columbus-based research firm Battelle and $11 million in federal funding. Officials said the project could help reduce climate change and increase U.S. oil production.
Two energy plants about 40 miles from the test site emitted a combined 23.1 million tons of carbon dioxide in 2010, state officials said. The companies are testing a process that would draw a stream of carbon dioxide that could be sold for injection into the oil wells.
Environmentalists have criticized the plan, saying a substantial amount of carbon dioxide returns to the surface with the oil.
"I don't doubt the workability of enhanced oil recovery," Nachy Kanfer, the Midwest coordinator of the Sierra Club's coal-to-clean-energy campaign, told the Dispatch. "I doubt carbon dioxide's ability to remain underground."