Sunk oil rig sparks fears of environmental crisis
Updated on 26 April 2010
Environmentalists have expressed concern that a sunk drilling rig off the US coast could cause an environmental disaster as oil spills out into the Gulf of Mexico.
US Coastguards said last week they did not believe the Deepwater Horizon drilling platform was leaking oil.
However it has now emerged up to one thousand barrels of oil a day is spewing out of the rig.
Four underwater vehicles have already been deployed under the plan outlined by the coast guard and US Minerals Management Service. They will dive unmanned to the ocean floor to activate a blowout preventer - a giant series of pipes and valves that could plug the leak.
The Deepwater Horizon, which was leased by oil giant BP, sank last Thursday after burning for at 36 hours, following an explosion.
Some 115 workers were rescued from the rig, but 11 people are still unaccounted for. They are presumed dead and the search for them has now been called off, following a weekend of bad weather.
London-based BP has sent an armada of ships and aircraft to containt the oil slick. The company is financially responsible for the clean-up operation.
Weather models predict the slick will remain 30 miles off shore for the next three days.
Coast Guard Rear Admiral Mary Landry said: "We have no shoreline impacts at this time."
The oil currently covers around 400 square miles so the blowout preventer is vital to contain the slick.
BP's chief operating officer of exploration and production, Doug Suttles said that the blowout preventer is a "highly complex task" and "it may not be successful".
The blowout preventer weighs around 450 tons and sits on the ocean floor next to the well. Experts say it could take up to 36 hours to activate.
As backup, BP has sent two floating drilling rigs to the scene that could drill a series of relief wells to stop the leak. However, that operation could take months.
At present, the spill is not comparable with the Exxon Valdez disaster in 1989. That spilled out 11 million gallons of oil into the Prince William Sound in Alaska when it ran aground. The well in the Gulf of Mexico is spewing out around 42,000 gallons of oil a day.
The explosion came three weeks after President Barack Obama announced plans for a limited expansion of US offshore oil and gas drilling. So far it has not affected US oil markets.