Chaparral Energy searches the scrublands of America's Mid-Continent and Permian Basin, looking for oil and natural gas. The exploration and production subsidiary of Chaparral Energy Inc. also drills in North Texas, the Gulf Coast, the Ark-La-Tex region, and the Rocky Mountains. In 2012 it reported proved reserves of some 146.1 million barrels of oil equivalent. Some of its reserves are in enhanced oil recovery project areas, primarily in Oklahoma and Texas, where the company uses carbon dioxide (CO2) to flood wells to release trapped oil in mature and well-worked fields. Securing CO2 supply from third party plants is key to its enhanced oil recovery, an area of expertise the company has pursued since 2000.