ExxonMobil Corporation announced two major oil discoveries and a gas discovery in the deepwater Gulf of Mexico after drilling the company”s first post-moratorium deepwater exploration well. ExxonMobil estimates the wells hold the potential for 700 million barrels of recoverable oil equivalent, which would make the oil discover the largest in the Gulf of Mexico in the last decade.

The KC919-3 wildcat well, which ExxonMobil operates, confirmed the presence of a second oil accumulation in Keathley Canyon block 919. ExxonMobil says the well encountered more than 475 feet of net oil pay and a minor amount of gas in predominantly Pliocene high-quality sandstone reservoirs. The well, which is continuing to drill deeper, is located 250 miles southwest of New Orleans in approximately 7,000 feet of water.

Drilling in early 2010 encountered oil and natural gas at Hadrian North in KC919 and extending into KC918, with over 550 feet of net oil pay and a minor amount of gas in high-quality Pliocene and Upper Miocene sandstone reservoirs, according to ExxonMobil.

ExxonMobil encountered 200 feet of natural gas pay in Pliocene sandstone reservoirs at its Hadrian South prospect in Keathley Canyon block 964 during drilling in 2009.

“We estimate a recoverable resource of more than 700 million barrels of oil equivalent combined in our Keathley Canyon blocks,” said Steve Greenlee, president of ExxonMobil Exploration Company, in a prepared statement. “This is one of the largest discoveries in the Gulf of Mexico in the last decade. More than 85 percent of the resource is oil with additional upside potential.”

ExxonMobil is the operator of KC918, KC919, KC963 and KC964 with 50 percent working interest. Eni Petroleum US LLC and Petrobras America Inc. each hold a 25 percent working interest in KC919, KC963 and KC964. Petrobras America Inc. holds a 50 percent working interest in KC918.

Over the past decade, ExxonMobil has drilled 36 deepwater wells in the Gulf of Mexico in water ranging from 4,000 feet to 8,700 feet.