(CNN) -- Oil company BP will attempt to insert a new section of pipe into the riser of its damaged undersea well to capture the gusher of crude now spewing into the Gulf of Mexico, a company spokesman said Thursday.
The operation could begin Thursday night, BP spokesman John Crabtree said. The goal is to use the new section of pipe, which is ringed with a gasket, to seal the 22-inch riser pipe -- the section that connects the well with the main pipe running to the surface -- then pump the oil up to a ship on the surface.
The new attempt is the latest plan by BP to seal the well that was uncorked when the drill rig Deepwater Horizon exploded April 20 and sank two days later, about 50 miles off the southeast coast of Louisiana, leaving 11 workers lost at sea. A previous effort to cap the gusher with a four-story containment dome failed when natural gas crystals collected inside the structure, plugging an outlet at the top.
If the new plan fails, BP could try using a smaller containment dome -- dubbed a "top hat" -- that would be injected with alcohol to act as an antifreeze and keep its outlet clear. And still under consideration is a proposal to plug the damaged well's blowout preventer, which has failed to cut off the leak, with debris such as ground-up rubber and plastic from old tires and golf balls.
The debris would be injected at high pressure into the blowout preventer, a 450-ton device that sits atop the wellhead. If that succeeds, the well would be injected with cement to seal it.
Adm. Thad Allen, the commandant of the Coast Guard, said Thursday the well is being studied to determine which of those methods is most likely to succeed.
"A sequence of events are going to be occurring over the next week that will be very, very determinant of where to go on this," Allen said.
The well has been pouring an estimated 210,000 gallons (5,000 barrels) of light, sweet crude into the Gulf for three weeks now. But so far, natural forces, human effort and some good fortune have kept the spill from becoming all-out environmental disaster, scientists said.
An oily sheen has reached the shores of some of Louisiana's barrier islands, but there has been no repeat of disastrous scenes of widespread oil-soaked wildlife and beaches, as in the 1989 wreck of the supertanker Exxon Valdez in Alaska's Prince William Sound.
"One of the things that's been happening is, the weather has worked in our favor so far," said Steven Lohrenz, marine science chairman at the University of Southern Mississippi. Ocean currents and prevailing winds have carried much of the spilled oil away from the coast, although the wind has changed in the past week, he said.
"The currents are very complex in that area, and they change pretty dramatically, so it's very difficult to predict what they will do," he said.
BP, the Coast Guard, and state and local authorities have scrambled to keep the oil from reaching shore or the ecologically delicate coastal wetlands off Louisiana. They have burned off patches of the slick, deployed more than 280 miles of protective booms, skimmed as much as 4 million gallons of oily water off the surface of the Gulf and pumped more than 400,000 gallons of chemical dispersants onto the oil.
Nevertheless, oil has washed up on barrier islands in Louisiana's Breton and Chandeleur sounds, spread west of the Mississippi River, and balls of tar associated with the spill have been reported as far east as Dauphin Island, off the Alabama coast. And the federal government has closed the area to commercial fishing, curtailing one of the region's biggest industries.
"No money's coming in. The shrimping's closed right now," said Luke Harris, a fisherman in Pass Christian, Mississippi. "Our oyster season is closed. There's a lot of boats that are able to get hired on by BP to help with the oil cleanup. We've got a lot of people on standby waiting to make a difference," he said.
Gulf Coast residents have been through disasters such as hurricanes before, including the massive Hurricane Katrina in 2005.
"But the day after a hurricane comes, you pretty much know what you have to deal with," Harris said. "With this disaster, we don't know what's going to come in here. We don't know when they can stop it."
The cause of the disaster is still under investigation. BP, which hired the doomed rig from drilling contractor Transocean Ltd., has blamed the owner for the April 20 explosion. Transocean says that BP was responsible for the wellhead's design and that oilfield services contractor Halliburton was responsible for cementing the well shut once drilled. And Halliburton says that its workers were just following BP's orders, but that Transocean was responsible for maintaining the rig's blowout preventer.
Witnesses have said a rush of gas that blew drilling fluid out the top of the rig's derrick preceded the explosion. And the chairman of a congressional committee looking into the disaster said Wednesday that BP knew the well failed a key pressure test hours before the explosion, indicating that oil or gas was seeping in.
"Yet it appears the companies did not suspend operations, and now 11 workers are dead, and the Gulf faces an environmental catastrophe," said Rep. Henry Waxman, D-California, the chairman of the House Energy and Commerce Committee.
Executives from the three companies working on the well said the events leading up to the explosion are under investigation and will come to light over time. But a leading member of Waxman's committee, Michigan Democrat Bart Stupak, told CNN's "American Morning" on Thursday that there was a clear "red flag" before the explosion.
"We know there was a conversation, but, unfortunately, those people who had that conversation, how those decisions were made, some are no longer with us," Stupak said. "And it's hard to make that determination what happened within there. There was a checklist that they went through. There were some communications, and then the whole thing erupted."
CNN's Aaron Cooper and Jim Kavanagh contributed to this report.