NEW ORLEANS (AP) — BP claimed a key victory Wednesday in the effort to plug its blown-out well as a government report said much of the spilled oil is gone — though what's left is still nearly five times the amount that poured from the Exxon Valdez.
Meanwhile, President Barack Obama is applauding headway that has been made to stop the nation's worst oil spill, saying the Gulf of Mexico operation is "finally close to coming to an end."
He said people's lives "have been turned upside down" as a result of the April 20 BP oil spill, but said he was heartened by indications the spill is, at last, being brought under control.
More than three months after oil began gushing from the sea floor, officials offered cautious remarks indicating that an end to one of the world's worst spills was in sight while some Gulf Coast residents expressed skepticism.
BP PLC reached what it called a significant milestone overnight when mud that was forced down the well held back the flow of crude. That means the procedure known as a "static kill" appears to be working, though crews now must decide whether to follow up by pumping cement down the broken wellhead.
Federal officials won't declare complete victory until they also pump in mud and then cement from the bottom of the well, and that won't happen for several weeks.
"We've pretty much made this well not a threat, but we need to finish this from the bottom," retired Coast Guard Adm. Thad Allen, the government's point man on the spill response, told WWL-TV in New Orleans.
About one-quarter of the BP oil that spilled out of its broken well remains in the Gulf, according to a report to be released Wednesday by scientists with the Interior Department and National Oceanic and Atmospheric Administration.
Nearly three-quarters of the oil — more than 152 million gallons — has been collected at the well by a temporary containment cap, been cleaned up or chemically dispersed, or naturally deteriorated, evaporated or dissolved.
"It was captured. It was skimmed. It was burned. It was contained. Mother Nature did her part," White House energy adviser Carol Browner said on NBC's "Today" show.
That leaves about 53.5 million gallons in the Gulf. The amount remaining — or washed up on the shore — is still nearly five times the size of the 11 million-gallon Exxon Valdez spill, which wreaked environmental havoc in Alaska in 1989.
About a quarter of the oil evaporated or dissolved in the warm Gulf waters, the same way sugar dissolves in water, federal officials said. Another one-sixth naturally dispersed because of the way it leaked from the well. Another one-sixth was burned, skimmed or dispersed using controversial chemicals.
More than 205 million gallons gushed from the well after the Deepwater Horizon rig exploded off Louisiana on April 20, according to government estimates. Crews managed to burn, skim or siphon off more than 30 million gallons in the days after.
Charter boat captain Randy Boggs, of Orange Beach, Ala., said Wednesday he has a hard time believing BP's claims of success with the static kill and similarly dismissed the idea that only a quarter of the oil remains in the Gulf.
"There are still boats out there every day working, finding turtles with oil on them and seeing grass lines with oil in it," said Boggs, 45. "Certainly all the oil isn't accounted for. There are millions of pounds of tar balls and oil on the bottom."
A 75-ton cap placed on the well in July has been keeping the oil bottled up inside over the past three weeks but was considered only a temporary measure. BP and the Coast Guard wanted to plug up the hole with a column of heavy drilling mud and cement to seal it off more securely.
The static kill — also known as bullheading — involved slowly pumping the mud from a ship down lines running to the top of the ruptured well a mile below. A previous, similar effort failed in May when the mud couldn't overcome the unstemmed flow of oil.
BP won't know for certain whether the static kill has succeeded until engineers can use the soon-to-be-completed relief well to check their work.
In the Gulf, workers stopped pumping mud in after about eight hours of static kill work and were monitoring the well to ensure it remained stable, BP said.
"It's a milestone," BP PLC spokeswoman Sheila Williams said. "It's a step toward the killing of the well."
The pressure in the well dropped quickly in the first 90 minutes of the static kill procedure, a sign that everything was going as planned, wellsite leader Bobby Bolton told The Associated Press on Tuesday.
Browner told NBC it was good news that the static kill was working but that "we remain focused on the relief well."
BP has said the static kill might be enough by itself to seal the well. But the 18,000-foot relief well that BP has been drilling for the past three months will be used later this month to execute the "bottom kill," in which mud and cement will be injected into the bedrock 2½ miles below the sea floor to finish the job, Allen said Tuesday.
"There should be no ambiguity about that," Allen said. "I'm the national incident commander, and this is how this will be handled."
The task is becoming more urgent because peak hurricane season is just around the corner, Allen said. Tropical Storm Colin formed then dissipated far out in the Atlantic on Tuesday, but early forecasts say it will travel toward the East Coast rather than the Gulf.
Weber reported from aboard the Q4000. Contributing to this report were Associated Press writers Dina Cappiello in Washington, Jay Reeves in Birmingham, Ala., Bernard McGhee in Atlanta, Robert Barr in London and Ramit Plushnick-Masti in Houston.