BP starts oil well mud plugging
BP engineers have begun pumping heavy drilling mud into the blown-out Gulf of Mexico oil well in what they believe is their best yet chance to snuff out for good one of the world's largest spills.
Crews began the long-awaited effort dubbed the "static kill", which involves pumping mud and eventually, crews hope, cement from ships to the well bore a mile below to seal off the source of the oil.
But the US government and oil executives will not declare victory until crews also pour mud and cement down an 18,000ft relief well later this month to help choke the vast undersea reservoir that feeds the wrecked Deepwater Horizon well - the only way, they say, to make certain oil never escapes again.
Meanwhile, Michael Bromwich, who as director of the Bureau of Ocean Energy Management, Regulation and Enforcement is America's top drilling regulator, said the Obama administration hoped to lift a freeze on deep-water drilling before it is due to expire on November 30.
Tests for the static kill started a couple of hours earlier as BP probed the broken well bore with an oil-like liquid to determine whether there were any obstructions in the well and to assess the pressure of the bore and the pump rates it could withstand.
The test "went exactly as we could have expected" but it's too early to tell whether the static kill is successful, said BP senior vice president Kent Wells, adding: "We're so early in the process there's no way for me to give you any early indication. We're extremely focused on this point on making sure we execute the static kill as best we can."
Crews should know within hours whether the mud is pushing down the oil as envisaged. But engineers still will not know for more than a week whether the attempt achieved its goal because they have to wait for completion of the relief well.
"This is a really positive step forward," retired US Coast Guard Admiral Thad Allen said, calling it "good news in a time where that hasn't been very much good news, but it shouldn't be a cause for premature celebration".
BP officials said earlier the static kill alone - which involves slowly pumping the mud down lines running from ships a mile above - might be enough to plug the oil leak.
But the only sure way to make certain the well is permanently plugged is to also fill it with mud and cement via the relief well in a so-called "bottom kill", said Admiral Allen, the US government's point man on the spill response. The relief well is set for completion as early as August 11. The static kill could take days to complete, mostly because it involves slow pumping of mud, he said.