Knotty Head was at one point the deepest oil well in the Gulf of Mexico

Gulf of Mexico

The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

. It is drilled in 3500 ft (1,067 m) of water and 30589 ft (9,323.5 m) below the sea floor. It is jointly owned by Chevron

Chevron Corporation

Chevron Corporation is an American multinational energy corporation headquartered in San Ramon, California, United States and active in more than 180 countries. It is engaged in every aspect of the oil, gas, and geothermal energy industries, including exploration and production; refining,...

, Anadarko Petroleum Corporation

Anadarko Petroleum Corporation

Anadarko Petroleum Corporation is one of the world’s largest independent oil and gas exploration and production companies, with approximately 2.3 billion barrels of oil equivalent of proved reserves and production of 206 million BOE as of December 31, 2008. Anadarko employs a worldwide...

, BHP Billiton

BHP Billiton

BHP Billiton is a global mining, oil and gas company headquartered in Melbourne, Australia and with a major management office in London, United Kingdom...

 and Nexen Inc. with each having 25% of the share. Initially, the well was estimated to hold 350 million to one billion barrels of oil, but additional tests have cut that estimate down to 200 million to 500 million. The field is located in the Green Canyon Area, section 512.