Anadarko is among the largest independent oil and natural gas exploration and production companies in the world, with 2.54 billion barrels of oil equivalent (BBOE) of proved reserves at year-end 2011. The company's portfolio of assets encompasses premier positions in U.S. onshore shales and resource plays in the Rocky Mountains region, the southern United States and the Appalachian Basin. The company also is a premier deepwater producer in the Gulf of Mexico, and has production in Alaska, Algeria, and Ghana with additional exploration opportunities in West Africa, Mozambique, Kenya, South Africa, New Zealand and China.