WASHINGTON — The Obama administration on Thursday ordered BP to remove the failed blowout preventer from its Deepwater Horizon well in the Gulf of Mexico and preserve it as likely evidence in civil and criminal investigations.
Retired Coast Guard Adm. Thad Allen issued the instruction after a week of what he called "intense negotiation" between BP and government scientists over how to proceed with completing a relief well that BP has been drilling since May 2.
Allen has called the relief well the only way to be certain that the BP well is dead. Previously, he'd predicted that the relief well would be completed this week. The new instruction will push back that date until sometime after Labor Day, Allen said.
"We do not want to have damage to the blowout preventer," he said in explaining the delay. "We are concerned about preserving evidence."
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Why the blowout preventer — a giant collection of valves designed to sever a deepwater well's drilling pipe in the event of an emergency — didn't work has been a key question for investigators probing the April 20 explosion that killed 11 oilrig workers and sparked a gusher that caused billions of dollars in economic damages along the Gulf Coast.
BP officials told Congress in May that diagrams they had of the blowout preventer were inaccurate and that they wasted days trying to activate its shearing mechanisms. Other reports have raised questions about how the device had been modified and maintained, including a failure to repair a hydraulic leak that may have undermined its ability to shear through the drill pipe.
The blowout preventer actually is owned by Transocean, the company from which BP had leased the Deepwater Horizon drilling rig. BP and Transocean have blamed one another for the blowout preventer's failure to seal the well.
In telling BP to replace the blowout preventer, Allen's written order specified "each procedure should recognize and preserve the forensic and evidentiary value of the BOP and any material removed from the BOP."
"None of the procedures may be performed prior to my approval," Allen's order said.
It was not clear how or if law enforcement officials would monitor the recovery of the blowout preventer, which BP Senior Vice President Kent Wells said would be brought to the surface by the Q4000 drilling rig and then ferried to shore. The Department of Justice declined to comment.
Allen, the Obama administration's point man on the oil crisis, told reporters in a briefing here that the blowout preventer would be critical both to a criminal investigation being undertaken by a Justice Department task force and to a joint investigation into the causes of the blowout by the Coast Guard and the Interior Department agency formerly known as the Minerals Management Service. The MMS was renamed the Bureau of Ocean Energy Management, Regulation and Enforcement in the wake of the Deepwater Horizon catastrophe.
Allen did not specify the points of contention in talks over the past several days between BP and government scientists, led by Energy Secretary Steven Chu, a Nobel Prize wining physicist.
It has been clear for several weeks, however, that the two sides were not of one mind on how to proceed after BP used heavy drilling mud to force crude oil out of the Deepwater Horizon well and back into the rock formations from which it had surged 13,000 feet beneath the seafloor. BP then poured cement into the well and pronounced it sealed.
Officials have said repeatedly since then that there's no oil seeping out of the reservoir into the drill pipe or the well's annulus, the space between the outside of the drill pipe and the rock wall of the wellbore. The Obama administration has gone so far as to declare that three-quarters of the oil that had escaped from the well has been dispersed or evaporated.
Allen said Thursday, however, that engineers still are uncertain why the well appears to be sealed. He said some government scientists fear that a blockage between the reservoir and the well's annulus may be the result simply of a collapse of rock formations and not a permanent seal with cement.
Easing those fears by placing cement in the annulus via the relief well raises new risks of undoing the seals already in place. Allen said the delay in completing the relief well will allow BP to undertake a series of steps to lessen that danger.
The first, Allen said, would be to remove any drilling mud and cement from the current blowout preventer and a containment cap that sealed the well in July and replace it with much lighter seawater. BP's Wells told reporters that that process was completed overnight, with BP reconnecting a drill ship on the surface to the containment cap to capture the drilling mud and crude oil.
Technicians will then monitor the well for 48 hours before undertaking what Allen called a "fishing experiment" to remove the well's drill pipe from the blowout preventer. That step, Allen said, is necessary to make certain that moving the blowout preventer doesn't damage the 5,000 feet of cement currently sealing the well.
Finally, a new blowout preventer will be brought in to replace the old one. Preparing the old blowout preventer for removal and testing the new one, in addition to the other steps, "takes you to after Labor Day," Allen said.
Wells said that there would be no blowout preventer over the well for 24 hours while the switch is accomplished, but that officials were confident no oil would escape during that time.
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