Wednesday, June 30, 2010
The Department of Energy says that drill pipe from the BP pil well was violently ejected upwards into the blowout preventer.
As the Los Angeles Times notes today:
A team of scientists from the Energy Department discovered a new twist: Their sophisticated imaging equipment detected not one but two drill pipes, side by side, inside the wreckage of the well's blowout preventer on the bottom of the Gulf of Mexico.While the DOE is only referring to drill pipe and not well casing, many experts have said that the well casing was destroyed also.
BP officials said it was impossible. The Deepwater Horizon rig, which drilled the well, used a single pipe, connected in segments, to bore 13,000 feet below the ocean floor. But when workers cut into the wreckage to install a containment cap this month, sure enough, they found two pipes.
The discovery suggested that the force of the erupting petroleum from BP's well on April 20 was so violent that it sent pipe segments hurtling into the blowout preventer, like derailing freight cars.
It also offered a tantalizing theory for the failure of the well's last line of defense, the powerful pinchers called shear rams inside the blowout preventer that should have cut the pipe and stopped the rising oil and gas from reaching the Deepwater Horizon 5,000 feet above. Drilling experts say those rams, believed to be partially deployed, could have been thwarted by the presence of a second pipe.
The doubled-up drill pipe joins a list of clues that is helping scientists understand the complexities of the Deepwater Horizon accident, and from that, craft changes in how deep-water drilling is conducted.
"We still don't really know what's in" the well wreckage, said Energy Secretary Steven Chu, whose team discovered the second pipe using gamma-ray imaging. He added: "If there were two drill pipes down there when the shear rams closed, or two drill pipes below, is it possible that in the initial accident … there was an explosive release of force?…Did it buckle and snap?…The more we know about this, the better we can know what to do next."
Indeed, the government is making back-up plans in case the relief wells don't work. As the New York Times reported yesterday:
BP and government officials are now talking about a long-term containment plan to pump the oil to an existing platform should the relief well effort fail. While such a failure is considered highly unlikely, the contingency plan is the latest sign that with this most vexing of engineering challenges — snuffing a gusher 5,000 feet down in the gulf — nothing is a sure thing.
Experts said it was conceivable that the “kill” procedure would not be effective, particularly if only a single relief well was used and the bottom of the well bore was damaged in the initial blowout. Pumping large quantities of erosive mud into the well could even end up damaging the well further, hindering later efforts to seal it.
“I won’t say there haven’t been relief wells that haven’t worked,” said a technician involved in the effort.
There are questions about the damaged well’s condition, particularly near the point where the interception would take place, and whether it could affect the kill procedure.
“No human being alive can know the answers,” said the technician, who spoke on condition of anonymity because he was not authorized to comment on the work.