BP's Thunder Horse Platform in the Gulf of Mexico © BP plc.

Oil giant BP announced today a giant oil discovery at its Tiber Prospect in the deepwater of the Gulf of Mexico.

The well, located in Keathley Canyon block 102, approximately 250 miles (400 kilometres) south east of Houston, Texas, is in 4,132 feet (1,259 metres) of water. The Tiber well was drilled to a total depth of approximately 35,055 feet (10,685 metres) making it one of the deepest wells ever drilled by the oil and gas industry. The well found oil in multiple Lower Tertiary reservoirs. Appraisal will be required to determine the size and commerciality of the discovery.

"Tiber represents BP's second material discovery in the emerging Lower Tertiary play in the Gulf of Mexico, following our earlier Kaskida discovery," said Andy Inglis, chief executive, Exploration and Production. "These material discoveries together with our industry leading acreage position support the continuing growth of our deepwater Gulf of Mexico business into the second half of the next decade."

Tiber is operated by BP with a 62 per cent working interest with co-owners Petrobras, the Brazilian oil producer (20 per cent) and ConocoPhillips (18 per cent).

BP is the largest producer of oil and gas in the Gulf of Mexico with net production of over 400,000 barrels of oil equivalent per day. BP says it is progressing nine Gulf of Mexico projects: Atlantis Phase 2, Tubular Bells, Kodiak, Freedom, Kaskida, Isabela, Santa Cruz, Mad Dog tiebacks and Great White.

Major BP developments in the deepwater Gulf of Mexico include: Pompano, 1994; Marlin, 2000; Horn Mountain, 2002; Na Kika, 2003; Holstein, 2004; Mad Dog, 2005, Atlantis, 2007, Thunder Horse 2008.

BP says it has a leading acreage position in the emerging Lower Tertiary area of the Gulf of Mexico. BP's first major discovery in the Lower Tertiary was Kaskida in 2006 which is currently under appraisal.