Mitsui Oil Exploration Mitsui Oil Exploration It was one of 17 Mitsui companies that were spun off on July 19, 1969. Its core areas are Thailand, where it drills principally in the Gulf of Thailand in conjunction with Chevron, and Vietnam and Cambodia. In the United States Mitsui's subsidiary is MOEX USA Corp and is headquartered in 9 Greenway Plaza in Houston. In September 2007 it established subsidiary MOEX Offshore 2007 LLC which entered into a partnership with BP for drilling in the Gulf of Mexico. On April 20, 2010, its rig the Deepwater Horizon exploded and sank, causing a massive oil spill.
Volume and extent of the Deepwater Horizon oil spill collected before it could enter the Gulf waters. In its permit to drill the well, BP estimated the worst-case flow at . Immediately after the explosion the USCG did not estimate any oil leaking from the sunken rig or from the well. On 24 April, USCG Rear Admiral Mary Landry announced that a damaged wellhead was indeed leaking. She stated that "the leak was a new discovery but could have begun when the offshore platform sank . . . two days after the initial explosion." Initial estimates by USCG and BP officials, based on remotely operated vehicles as well as