Oil industry expert Matt Simmons has said for many weeks that the well casing was destroyed by the initial explosion at the Deepwater Horizon rig. He said that when oil wells blow out, the casing often shoots up above ground.
He has been ridiculed by many because no one has seen well casing on the seafloor.
But the Department of Energy has just partly exonerated Simmons. 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.
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.”
In other words, the explosion apparently did cause portions of the well casing to shoot upward. But the upward thrust of the destroyed segment of casing was stopped by the blowout preventer. (Simmons’ theory that the wellhead had ended up several miles from the drilling location might not be correct, and the theory that casing got jammed into the blowout preventer might, instead, be the correct one).
As I wrote on June 12th:
As noted yesterday in The Engineer magazine , an official from Cameron International – the manufacturer of the blowout preventer for BP’s leaking oil drilling operation – noted that one cause of the failure of the BOP could have been damage to the well bore:
Steel casing or casing hanger could have been ejected from the well and blocked the operation of the rams.
This could, in fact, be part of what caused the blowout preventer to fail (although it does not absolve BP of criminal negligence).
As I have repeatedly pointed out, substantial destruction of the well casing could cause the relief wells to fail.
Indeed, 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.
This article was posted: Wednesday, June 30, 2010 at 3:46 am