BP Oil Spill: 'Static Kill' Seals off Well, as President Obama Says Most of Oil Is Gone

On the 107th day of the oil spill crisis in the Gulf of Mexico, the blown-out well from which discharged about 200 million gallons of crude escaped is finally sealed for good, BP and the federal government say.

"The long battle to stop the leak and contain the oil is finally coming to an end," President Obama said this morning before a meeting of the AFL-CIO executive committee in Washington, D.C.

Its Official: Oil Leak KilledPlay
It's Official: Oil Leak Killed

Watch 'World News with Diane Sawyer' for the latest on the oil spill tonight on ABC.

BP's "static kill" operation finished ahead of schedule. It took eight hours to fill the 13,000-foot well pipe with heavy drill mud, holding back the oil with its weight. Since July 15, the oil had been contained by a temporary stacking cap.

Now, the column of mud ensures that oil will never be released from the well again, officials say. A permanent cement plug will be put in place later this month.

VIDEO: Carol Browner Play
Gulf Oil Spill: White House Says BP Containment a Turning Point

On top of the good news at the spill site, the federal government said today that about 75 percent of the oil that has been released since the start of the spill in April is no longer a threat.

"A report out today by our scientists shows that the vast majority of the spilled oil has been dispersed or removed from the water," Obama said.

Most of the oil was taken care of by Mother Nature -- either consumed by deepwater bacteria or simply evaporating. The fleet of some 800 skimmers only mopped up about 3 percent of the crude.

No Apology for Controversial BP CEO

In light of the news, ABC's Yunji de Nies posed a question to Press Secretary Robert Gibbs at the White House today, asking if BP CEO Tony Hayward is owed an apology. Hayward earned public scorn for comments suggesting that the environmental impact of the spill would be limited, given the size of the spill in relation to the Gulf.

VIDEO: Latest on the Oil LeakPlay
Gulf Oil Spill: BP Reports 'Static Kill' Success

"Nobody owes Tony Hayward an apology," Gibbs said, insisting that much of the success in controlling the spill was due to pressure from the federal government. "We asked for and demanded that, particularly, their containment strategy be accelerated."

Obama and Gibbs both promised that the federal government will continue to work with the people of the Gulf to ensure that recovery continues and that victims of the spill are reimbursed.

"We're going to stand by the people of the region, however long it takes, until they're back on their feet," Obama said.

Remaining Oil Still Far Larger Than Exxon Valdez Spill

Even if the 75 percent figure holds, however, the remaining 25 percent of oil still in the Gulf could amount to more than 50 million gallons, based on revised government estimates of the spill rate issued Tuesday. That alone would still rank as the worst oil spill in U.S. history, far larger than the 11 million-gallon Exxon Valdez spill in 1989.

Echoing the fears of some people along the Gulf Coast about an early pullout of cleanup operations, Plaquemines Parish President Billy Nungesser told ABC's Diane Sawyer Monday that oil is still hitting shorelines, saying his crews had vacuumed thick black crude from Barataria Bay this the weekend.

"I wish there was no oil, I'd rather get my life back, too. But, everyday, oil is appearing somewhere," Nungesser said. "Make no mistake, there's large areas that are totally destroyed, and the greenery is completely dead."

Carol Browner, director of the White House Office on Energy and Climate Change, said today that the remaining 25 percent poses little concern.

"That will continue to weather. Mother nature will continue to break it down," she said. "Some of it may come on shore as weathered tar balls, and those will be cleaned up."

Relief Wells Will Continue for Final, 'Cement Kill'

Even with the apparent success of the "static kill," BP's job at the site of the collapsed Deepwater Horizon rig is still undone.

Although there was some thought from the company that the mud alone would be enough to plug the well permanently, the federal government has urged it to replace the mud with cement in a "final kill."

"We've pretty much made this well not a threat, but we need to finish this from the bottom," National Incident Cmdr. (retired) Thad Allen told New Orleans' WWL-TV.

BP will pump in cement through the top of the well, and it will also conduct a "bottom kill," pumping cement through the relief wells that are 100 feet from the target, a company spokesman said today.

The cementing process could be complete in as little as two weeks, Browner said.

No matter what, BP executive Kent Wells said Tuesday, "We want to end up with cement in the bottom of the hole."

ABC News' Jeffrey Kofman and Matt Gutman contributed to this story. Additional information from The Associated Press.

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