A gas tied to climate change could someday bring new life to old Ohio oil fields.
State officials are investigating whether carbon dioxide could be used to draw millions of barrels of crude oil from fields that were all but played out.
Energy companies have injected carbon dioxide into old oil fields in Texas and California for decades. The gas increases the pressure underground and mixes with the oil, freeing it from nooks and crannies.
"It lightens the oil. It fluffs it up," said Larry Wickstrom, chief of the Ohio Geological Survey. "It actually makes it so you can push (the oil) through."
Wickstrom oversaw Ohio's first test, during which 81 tons of carbon dioxide were pumped into a low-yield well about 10 miles southeast of Canton in Stark County.
After the injection in 2008, the well produced 58 percent more oil. The results were so promising that they inspired a state proposal for more-extensive testing by Columbus-based research giant Battelle and $11 million in federal funding.
Officials say the project could help reduce climate change and increase U.S. oil production.
"There is a substantial opportunity here," said Neeraj Gupta, Battelle's senior research leader for geological carbon storage.
The idea isn't embraced by all. Environmental advocates say that a substantial amount of carbon dioxide returns to the surface with the oil.
"I don't doubt the workability of enhanced oil recovery," said Nachy Kanfer, the Midwest coordinator of the Sierra Club's coal-to-clean-energy campaign. "I doubt carbon dioxide's ability to remain underground."
Carbon dioxide was first used in the oil fields of western Texas in 1972. Wickstrom said it hasn't been used in Ohio's oil fields because there is no readily available supply.
That might seem a little strange, considering the millions of tons of carbon dioxide that coal-fired power plants in Ohio emit each year. But capturing and transporting the gas is not cheap.
FirstEnergy's Sammis plant and American Electric Power's Cardinal plant, which are along the Ohio River, emitted a combined 23.1 million tons of carbon dioxide in 2010. They are within about 40 miles of the test site.
The process to draw a pure stream of carbon dioxide can consume one-third of a power plant's electricity. Power companies still are testing equipment that could do that.
Gary Spitznogle, AEP's director of new-technology development, said power plants probably would charge $80 to $100 per ton to cover their costs. He estimated that commercial carbon dioxide sells for $20 to $40 a ton.
Wickstrom and Gupta said the money made by wringing more oil out of the ground could help offset those costs.
The test site was at the 175,000-acre East Canton oil field in Carroll, Harrison, Stark and Tuscarawas counties. Officials say that more than 1 billion barrels might remain there. Pumping carbon dioxide into the wells could draw as much as 279 million barrels from the field.
A more-extensive test at the site, involving as much as 20,000 tons of carbon dioxide injected over months, would help to confirm those early estimates, officials say.
Wickstrom said the state and Battelle have applied for an $11 million U.S. Department of Energy grant to help conduct that test. They won't know until September whether they'll get the money.
In the meantime, Battelle is involved in several federally funded projects to see whether carbon dioxide can be safely injected and stored underground. It's also helping AEP test a system that captures and injects 1.5 percent of the carbon dioxide produced by its Mountaineer power plant in West Virginia.
As far as using carbon dioxide to free oil, a larger test also would show how much of the gas resurfaces with the oil.
Wickstrom said that, on average, 20 to 30 percent of the carbon dioxide that's injected comes back up.
Gupta said wells in Texas and California include equipment to capture the carbon dioxide that comes off the oil so that it can be recycled and reinjected.
"There is a huge economic potential for more oil supply and storage of CO2 if we can make this work," Gupta said.