The government has given BP the go-ahead to replace the failed blowout preventer in the Gulf of Mexico as a first step toward permanently plugging the Deepwater Horizon well that caused one of the worst oil spills in history.
Retired Coast Guard Adm. Thad Allen, the national incident commander for the disaster, gave the green light to replace the blowout preventer, or BOP, after engineers from the British oil giant expressed concern that they could break a temporary plug installed last month as part of the permanent "bottom kill" procedure.
In a letter addressed to top BP Group executive Bob Dudley, Allen said that based on a meeting of the Government Scientific Technical Team on Wednesday, he was authorizing the company to "proceed with the course of action to replace [the] BOP."
The bottom kill involves using a relief well drilled into the side of the main bore as a conduit to drive cement in, making the plug permanent. That was supposed to take place this month, but the replacement of the blowout preventer would delay the final capping by a few weeks, Allen said.
Now, the procedure will likely begin "sometime the week after Labor Day," he said.
The government believes the bottom kill procedure is necessary to declare the well dead once and for all.
Jeffrey Carter, an aide to the government's spill chief, told The Associated Press that the decision on the path forward was made overnight, just hours after Allen told reporters he wasn't giving a timeline.
Carter said he did not know why things came together so quickly or why it will take nearly three more weeks to begin the bottom kill.
Allen had said replacing the blowout preventer was the quicker of the two options that engineers were considering to relieve pressure that may build up when the relief well intersects the blown-out well. The other was to design a mechanism to attach to the current equipment.
A cap has kept oil from flowing for more than a month, but that's just a temporary solution. Heavy drilling mud and cement were later pumped in through the top of the well, significantly reducing the pressure inside it.
But Allen did set conditions on swapping the temporary cap with a much stronger one. Among other stipulations, the procedure should not release any more oil and must "preserve the forensic and evidentiary value" of the BOP, presumably so investigators can examine it to determine exactly why it failed April 20, when the Deepwater Horizon rig exploded and sank. Eleven workers died in the accident.