Gulf oil spill: Engineers grapple with new complications
BP engineers flushed crystalline gas and water formations, known as methane hydrates, out of a damaged blowout preventer atop their capped Gulf of Mexico oil well Monday, thus freeing blocked rams on the structure. The successful operation means that they can now proceed to try to detach the giant stack of pipes and valves from the well, according to retired Coast Guard Adm. Thad Allen, the administration's point man on the gulf oil spill.
Allen said that engineers can easily retrieve two pipe sections from the sea floor, one about 13 feet long and another 18 inches long. But he indicated that removing a third pipe, which extends into the damaged blowout preventer may be more complicated.
Allen's Tuesday briefing for news media came as BP, cooperating with government scientists, moves cautiously toward a final solution to the devastating oil spill that was set off by the April 20 explosion of its Deepwater Horizon drilling rig. Its damaged well has been capped since July 15, but must be permanently sealed by replacing the crippled blowout preventer atop the well.
Once a new blowout preventer is fitted onto the damaged well, then a nearly completed relief well can intercept it, allowing permanent cementing.
The original blowout preventer will be examined for evidence in criminal and civil proceedings against BP and other companies over the causes of the spill.
The engineering ordeal should be completed by the week after Labor Day, but Allen said he could not guarantee the timing. "We cannot attach a timeline yet, because we do not know the condition of the pipe," he said.
Allen sketched out three possible scenarios. If the third pipe is sheared, and hanging freely, it can be pulled out. If it is extends into the well, possibly as far as 3,000 feet below the sea floor, then engineers may have to cut it off, and possibly remove the damaged blowout preventer with the pipe.
However, if the pipe has adhered to cement that was previously pumped into the damaged well, engineers would have to take some time to figure out how to detach it.
"We are developing procedures ... on how to deal with the pipe and cut it off, "Allen said, adding that the issue is "how much pull should we put on the blowout preventer until we say, 'Wait a minute, there is contact with cement.' "
He said that cameras and fishing tools will be lowered into the massive equipment now capping the well to help determine how to proceed.
-- Margot Roosevelt