Anadarko Petroleum Corporation (Anadarko) is an independent exploration and production company. As of December 31, 2011, the Company had over 2.5 billion barrels of oil equivalent (BOE) of proved reserves. Anadarko's asset portfolio includes positions in onshore resource plays in the Rocky Mountains region, the southern United States, and the Appalachian basin. The Company is also independent producers in the deepwater Gulf of Mexico, and has production and exploration activities globally, including positions in high-potential basins located in East and West Africa, Algeria, China, Alaska, and New Zealand. The Company operates in three segments: Oil and gas exploration and production, Midstream, and Marketing. In August 2012, Western Gas Partners, LP acquired an additional 24% membership interest in Chipeta Processing LLC from Anadarko.