Anadarko makes discovery in Gulf of Mexico

Anadarko Petroleum Corporation announces an oil discovery at its West Tonga prospect on Green Canyon block 726 in the deepwater Gulf of Mexico. The discovery well, located in approximately 4,700 feet of water, was drilled to a total depth of 25,680 feet and encountered over 350 feet of net oil pay in three high-quality subsalt Miocene sands. Anadarko operates West Tonga with a 37.5% working interest. Partners in the discovery include StatoilHydro with a 25% working interest, Chevron with a 20.5% working interest and Shell with a 17% working interest.

West Tonga is indicative of our exploration program in the deepwater Gulf, which focuses on prospects in the Miocene and Lower Tertiary plays that have estimated recoverable resources of more than 100 million barrels of oil equivalent. Coupled with the Caesar discovery (Anadarko 20%, Shell 62.5% and StatoilHydro 17.5%), West Tonga gives Anadarko and our partners two significant fields that potentially could be tied back to the Constitution spar.

Anadarko also is drilling both the Atlas prospect located on Walker Ridge block 155, and the Terrebonne prospect located on Green Canyon block 452. Atlas is a 30,000-foot lower Miocene test, operated by Anadarko with a 68% working interest. Repsol E&P USA Inc. has a 20% working interest and Ridgewood Energy Corporation holds a 12% working interest. Terrebonne, which is operated by Woodside Energy (USA) Inc., is a 26,000-foot upper Miocene test. Anadarko has a 33.33% working interest in Terrebonne. Plains Exploration & Production Company holds a 25% working interest.