Abstract

Wyoming’s crude oil production and proved reserves have declined dramatically since 1970. In 2002, crude oil production was only 54.7 million barrels; production in 1970 reached an all-time high of 160.3 million barrels. Proved reserves have declined from over one billion barrels in 1970 to less than 500 million barrels at the end of 2001. Relatively high crude oil prices over the last several years failed to stimulate additional drilling for crude oil. Much of the U.S. Geological Survey’s mean estimated value of 3.3 billion barrels of undiscovered, technically recoverable resources of crude oil in Wyoming basins will never be discovered without increased drilling and increased access to federal lands. Much of the oil that is discovered will never be produced because of economic restrictions or development restrictions on federal land.

Wyoming’s best hope for reversing its declining oil production may be carbon dioxide (CO2) flooding. Targets for this method are in fields that contained in total approximately 8 billion barrels of original oil in place. Successful floods in these fields could recover up to 15% of the 8 billion barrels, or 1.2 billion barrels. The process has been successful at Lost Soldier and Wertz fields where an additional 62 million barrels (10% of the original oil in place in the Tensleep Sandstone) was recovered. A carbon dioxide flood planned by Anadarko Petroleum for Salt Creek Field may recover an additional 150 million barrels of oil. At peak production rates, the flood at Salt Creek alone will reverse Wyoming’s decline in oil production for a few years. Carbon dioxide floods in other large oil fields in Wyoming would also contribute to reversing the decline in oil production. Current oil prices should be enough to make carbon dioxide floods profitable if fields are reasonably close to a supply of carbon dioxide. There is reason to believe that credits will accrue to companies and states that effectively capture carbon dioxide and sequester it. These credits, as they are traded or sold, may become more valuable than the incremental oil.