CO2 is squeezing more oil out of Wyoming field

MIDWEST, Wyo. — By all accounts, the Salt Creek oil field was dying. Production had dropped from 6.3 million barrels in 1978 to 1.7 million in 2004, dragging Wyoming's statewide oil production down with it. By 2020, the field was expected to be dry.

But a project by Anadarko Petroleum Corp. using carbon dioxide to coax more oil out of the ground has revived the Salt Creek field so much that it is expected to single-handedly reverse the entire state's production decline.

It also will clear the landscape of thousands of unsightly power poles, power lines and conventional pumping wells, and prevent tons of greenhouse gases from polluting the atmosphere.

"It's good for the economy. It's good for the country. It's good for the environment," Anadarko spokesman Rick Robitaille said. "It's a very positive scenario."

After 100 years of drilling that yielded about 655 million barrels of oil, Salt Creek is now thought to still hold an estimated 1 billion barrels of oil. However, most of the remaining oil cannot be drawn out using conventional drilling methods, and eventually the falling oil yields would make it impractical to keep the field operating.

Anadarko hopes to draw at least another 200 million barrels of oil out of the field by injecting CO2 into the ground, pushing the oil toward new and previously drilled wells. That 200 million barrels of oil would be enough to supply all residential, commercial, industrial, transportation and power needs in the state of Michigan for all of 2001, the latest year for which figures are available.

Don Likwartz, director of the Wyoming Oil and Gas Conservation Commission, said the Salt Creek project is expected to increase overall oil production in the state through 2009.

"That is quite an accomplishment considering we had 19 years of decline," Likwartz said.

In the early 1970s, Wyoming wells pumped out nearly 160 million barrels a year. Oil fueled the state's economy and gave rise to towns like Midwest, which exist against a background of pumping oil wells.

By 2004, production statewide had dropped to just 51.6 million barrels.

The key to Salt Creek's revival and the revival of Wyoming's oil industry is the carbon dioxide. Conventional wells that dot the oil patch landscape of America aren't capable of reaching most of the oil stored underground.