Anadarko Announces Continued Deepwater Gulf of Mexico Success.

HOUSTON -- Anadarko Petroleum Corporation (NYSE:APC) today announced its successful participation in a significant oil discovery in the deepwater Gulf of Mexico.

In Green Canyon block 512, approximately 170 miles southeast of New Orleans, the Knotty Head discovery is the deepest ever drilled in the Gulf of Mexico. The Knotty Head discovery well, in approximately 3,500 feet of water, was drilled to a total depth of more than 34,000 feet, encountering approximately 600 feet of net pay sands in multiple zones. Analysis indicates high quality crude oil in good quality reservoir sands. Further drilling is planned to determine the extent of the discovery. Earlier this year the well was reported to have encountered more than 300 feet of apparent hydrocarbon pay based on measured-while-drilling logs through a depth of 29,670 feet.

Anadarko and partners BHP Billiton (NYSE:BHP), Chevron (NYSE:CVX) and Nexen Inc. (NYSE:NXY) each holds a 25 percent working interest in Green Canyon block 512, with Nexen serving as operator.

"The Knotty Head discovery is part of an extensive middle-to-lower Miocene play we are aggressively pursuing within the Mississippi fan foldbelt," said Bob Daniels, Anadarko Senior Vice President, Exploration and Production. "This success adds to our existing position in the general area, where the K2 and K2 North fields and this year's Genghis Khan discovery are expected to be producing through the Marco Polo facility in 2006. Along with a major development project underway in the eastern Gulf of Mexico, slated to come on line in 2007, Anadarko has captured significant deepwater production growth through the end of this decade."

A recent report from the U.S. Department of Interior's Minerals Management Service listed Anadarko as the operator with the most reported deepwater Gulf of Mexico discoveries in 2005, with drilling success at Mondo Northwest and the Jubilee extension in the eastern Gulf and at Genghis Khan in the foldbelt area.

"Including Knotty Head, we participated in four successful deepwater tests so far in 2005, with two additional wells - the Chevron-operated Big Foot and Shell-operated Pathfinder prospects - still in progress," Daniels said. "We expect to remain very active in the region in 2006 and well into the next decade, and have contracted deepwater drilling rigs to help support that program. The deepwater Gulf of Mexico will be a major piece of our overall growth plan."

Anadarko Petroleum Corporation's mission is to deliver a competitive and sustainable rate of return to shareholders by developing, acquiring and exploring for oil and gas resources vital to the world's health and welfare. As of year-end 2004, the company had 2.37 billion BOE of proved reserves, making it one of the world's largest independent exploration and production companies. Anadarko's operational focus in North America extends from the deepwater Gulf of Mexico, up through the Canadian Rockies and onto the North Slope of Alaska. Anadarko's international operations are focused on its major positions in Algeria, Venezuela and Qatar, and exploration or production operations in several other countries. For more information about how Anadarko is bringing excellence to the surface, please visit: www.anadarko.com.