Crews hoped to begin pumping mud and perhaps cement down the throat of the blown-out oil well at the bottom of the Gulf of Mexico on Tuesday in what BP officials said could be the method of attack that finally snuffs the spill.
Engineers planned to probe the busted blowout preventer with an oil-like liquid to determine whether it could handle attempt to stymie the oil. If the test is successful, they plan to spend Tuesday through Thursday pumping the heavy mud down the well.
Retired Coast Guard Adm. Thad Allen, the government's point man on the spill response, said Tuesday at a news briefing in Houston that crews hoped to begin the testing soon and finish by noon.
"This is a really positive step forward," Allen said of the impending operation, dubbed the static kill. "It's going to be good news in a time where that hasn't been very much good news, but it shouldn't be a cause for premature celebration."
The static kill is meant as insurance for the crews that have spent months fighting the spill. The only thing keeping oil from blowing into the Gulf at the moment is an experimental cap that has held for more than two weeks but was never meant to be permanent.
The hours-long testing was supposed to be completed Monday, but a minor leak discovered in the hydraulic control system pushed back the diagnostics until Tuesday. Allen said that leaks have been repaired and that engineers hope to launch the static kill Tuesday afternoon after reviewing test results.
"The quicker we get this done, the quicker we can reduce the risk of some type of internal failure" of the massive 75-ton cap that has bottled up the oil since mid-July, he said.
BP officials had insisted for months that a pair of costly relief wells were the only surefire way to kill the oil leak but said Monday that the static kill alone — involving lines running from a ship to the blown-out well a mile below — might do the trick.
BP Senior Vice President Kent Wells said that if the static kill is successful, the relief wells may not be needed to do the same thing weeks later, but from the bottom. The primary relief well, near completion, will still be finished and could be used simply to ensure the leak is plugged, he said.
"Even if we were to pump the cement from the top, we will still continue on with the relief well and confirm that the well is dead," he said. Either way, "we want to end up with cement in the bottom of the hole."
Allen added Tuesday that there "should be no ambiguity" that the primary relief well — which could be completed as early as Aug. 11 — will be finished regardless.
Government officials and company executives have long said the wells, which can cost about $100 million each, might be the only way to make certain the oil is contained to its vast undersea reservoir. A federal task force said about 172 million gallons of oil made it into the Gulf between April and July 15, when the temporary cap contained all the oil.
The task force said actually about 206 million gallons total gushed out of the mile-deep well but a fleet of boats and other efforts were able to contain more than 33 million gallons. The 172 million gallons is on the high end of recent estimates that anywhere from 92 million to 184 million gallons had gushed into the sea.
Judging by the latest estimate, BP could be fined up to $5.4 billion under the Clean Water Act, or as much as $21 billion if it is found to have committed gross negligence or willful misconduct.
The high-end fine would drop to around $17.6 billion if the government credits BP for the oil it has recovered, while the low-end fine would be around $4.5 billion.
Any fines would be on top of the compensation BP has agreed to pay to thousands of people harmed by the spill. Under pressure from the White House, the company set up a $20 billion escrow fund to pay all claims, including environmental damages and state and local response costs.
The company began drilling the primary, 18,000-foot relief well May 2, 12 days after the Deepwater Horizon rig exploded and killed 11 workers, and a second backup well May 16. The first well is now only about 100 feet from the target.
Tropical Storm Colin formed far out in the Atlantic on Tuesday, but early forecasts put it on a track off the East Coast rather than the Gulf.
BP and federal officials have managed to contain large parts of the spill through skimmers, oil-absorbant boom and chemical dispersants meant to break up the oil.
Federal regulators have come under fire from critics who say that BP was allowed to use excessive amounts of the dispersants, but government officials counter that they have helped dramatically cut the use of the chemicals since late May.
The Environmental Protection Agency released a study Monday concluding that when mixed with oil, chemical dispersants used to break up the crude in the Gulf are no more toxic to aquatic life than oil alone.
Contributing to this report were Associated Press writers Jeffrey Collins and Harry R. Weber in New Orleans, Ramit Plushnick-Masti in Houston, and Matthew Daly in Washington.
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