April 25 (Bloomberg) -- BP Plc said it may take at least two or three months to drill a relief well to stop a 1,000- barrel-a-day oil leak into the Gulf of Mexico after a drilling rig caught fire and sank last week. The company is also trying to shut the well's valve with robots. The oil spill, which covers 600 square miles (1,554 square kilometers), won't reach a shoreline within the next three days, said Charlie Henry, a scientific support coordinator with the National Oceanic and Atmospheric Administration during a teleconference today. Henry said it isn't possible to give estimates beyond three days.
Swiss drilling contractor, Transocean Ltd., is shipping in two rigs to stop the leak with the first scheduled to arrive tomorrow and the second May 2. The companies may need a relief well if the blowout valve isn't activated. A relief well would intercept the leakage and inject a heavy fluid to prevent oil or gas from escaping, London-based exploration company BP said in a separate statement. That would allow the well to be sealed.
"The relief well as described could take several months," Doug Suttles, BP's chief operating officer of exploration and production, said on the teleconference.
The response group, including BP and Transocean, began using remote operated vehicles at 8 a.m. local time today to try to switch on the blowout value, part of a 50-feet tall and 18- feet wide housing on the sea floor. It may take 24 to 36 hours to complete the work, Suttles said.
State of Louisiana
In some sensitive areas, Louisiana state authorities have begun installing booms, a type of floating net used to trap and gather any spilled oil on the water, as a precaution. Of the 600 square mile spill, 97 percent is considered oil sheen, or thin layer, above the water.
With more than 1,000 people working on the operation, costs total "several million dollars" so far, said Coast Guard Rear Admiral Mary Landry, who is overseeing the rescue and cleanup.
Oil is leaking out in two places at the site, said David Nicholas, a spokesman in London for BP, which is responsible for the cleanup. Thunderstorms, rain and rough seas are hampering efforts to clean up the spillage, according to a statement today from the Coast Guard, BP and Transocean.
The accident took place off the coast of Louisiana, where exploration was being carried out on the Macondo field. BP, the biggest oil producer in the Gulf of Mexico, had leased the Deepwater Horizon rig from Transocean for drilling.
The spill is about 30 miles from the coast, Landry said. It's unknown when the well can be capped, she said. The 1989 oil spill by the Exxon Valdez dumped 260,000 barrels near Alaska.
Anadarko, Mitsui
BP has a 65 percent stake in the project, with partners Anadarko Petroleum Corp. and Mitsui & Co. owning the remainder. The cost of the clean-up will likely be shared between the partners in line with their holdings, Nicholas said.
The fire on the rig started on April 20 after an explosion that Geneva-based Transocean said may have been caused by a so- called blowout, an unexpected surge in pressure that ejected petroleum at the top of the well. The rig sank two days later.
Eleven of the 126 workers on board are missing. A search for them was suspended and their families have been notified, Landry said.
It's the deadliest U.S. offshore rig explosion since 1968, when 11 died and 20 were injured at a platform owned by Gulf Oil Corp., according to data from the Minerals Management Service. A 1987 helicopter crash aboard a Forest Oil Corp. platform killed 14 people.
Nearby pipelines that were temporarily shut weren't affected by the rig's explosion and should soon be operating, Landry said. Royal Dutch Shell Plc's NaKika pipeline resumed crude transportation, the company said yesterday.
The Deepwater Horizon rig, which BP leased from Transocean, was found intact about 5,000-feet deep in the water and about 1,500 feet northwest of the well site, the Coast Guard said yesterday.
