Article Photos: Back to the Future: Chaparral hopes to recover 77 million barrels of oil from one of Oklahoma's oldest oil fields 4/10

Compressors at Chaparral Energy's North Burbank field in Osage County take carbon dioxide recovered from producing wells, compresses it before it is reinjected into the rock layers underground. Two compressors are operational, but the company plans to expand the facility to 16 units. <strong>photo by Adam Wilmoth</strong>