After days of deepening gloom, BP and two Obama administration officials suggested on Wednesday that the company was closer to a solution that might halt the seemingly uncontrollable oil spill in the Gulf of Mexico. The officials said engineers and scientists at BP’s command center in Houston had drafted plans to work on and around an underwater blowout preventer, a massive safety device that is designed to seal an oil well in an emergency, but failed to do so after the explosion at the rig on 20 April.Rico says that, if you make it expensive enough, they'll work harder at it next time...
The oil giant has “increasing confidence that we can intervene directly in the B.O.P. at acceptably low risk,” a BP spokesman, Andrew Gowers, said. Successive efforts to plug the spill over the past three weeks have failed.
Sent by President Obama to Houston, Energy Secretary Steven Chu and Interior Secretary Ken Salazar met with top engineers and scientists at the BP command center for several hours on Wednesday. “Things are looking up,” Dr. Chu, a Nobel laureate in physics, told reporters after the meeting. “Progress is being made.” He cautioned that the situation was still not under control and declined to detail the reasons for his optimism. But when pressed, he said, “I’m feeling more comfortable than I was a week ago.”
In Washington, a House subcommittee investigating the disaster raised the possibility that BP wrapped up work on the oil rig even though a seal at the top of the well had failed a pressure test a few hours before the explosion. Representatives also suggested that a hydraulic leak may have disabled the blowout preventer.
Yet as patches of oil washed ashore on a barrier island in Louisiana over sixty miles west of the Mississippi, a BP official said equipment was being put in place on the seabed for three intervention options that potentially could stop the spill within weeks rather than months. He said a decision would be made, most likely by Sunday, on whether to proceed with any of them. Work would begin a few days later, said the official, who spoke on condition of anonymity because he was not authorized to discuss the subject. He said ten robotic submersibles were carrying out the preparations 5,000 feet under the gulf’s surface in the meantime.
As the oil company that rented the drilling rig, BP is one of the parties responsible for stopping and cleaning up the spill. One option it has undertaken for halting the gush of oil is drilling relief wells that could be used to plug the damaged well with cement, but that will take several months.
Engineers have described three other approaches that could stop the leak: a so-called junk shot that would clog the blowout preventer with materials including shredded tires and golf balls; adding a second blowout preventer atop the first and using it to shut the flow; or cutting the collapsed riser pipe and installing a valve that would do the same thing.
The junk shot would be followed by a “top kill,” the pumping of heavy drilling mud into the well to overcome the pressure of the rising oil. The official said a junk shot might be used first even if another option was chosen because it could further restrict or stop the flow of oil and make the other repairs easier and safer. Installing a valve or a second blowout preventer, he said, would keep the well under control until a relief well was finished and heavy mud and cement could be pumped in to seal it permanently. The BP official said the material for the junk shot would be pumped from a ship on the surface through new pipe down to the blowout preventer, which the submersible robots have been working on for several days.
Officials noted that these kinds of approaches had never been tried at such depths and that they could fail, just as a plan to use a large containment dome to capture some of the oil failed over the weekend.
The junk shot technique was used successfully in the Kuwaiti oilfields in the 1991 Persian Gulf war. But those wells were on land and, even in harsh desert conditions, could be repaired by people, not by robots working in extremely cold water at a pressure of 2,300 pounds per square inch. But the BP official said pressure data made engineers hopeful that undertaking the work would not make the leak worse. That data was obtained from above the blowout preventer and below it, and the difference in readings showed that the blowout preventer is partly closed and actually restricting the flow. At the same time, gamma-ray inspection of the device showed that it “has external integrity”, the official said. Engineers had been concerned that if the device was damaged, working on it might make the leak worse.
The data from below the blowout preventer became available Sunday through a bit of serendipity, the official said: a robotic submersible suddenly started receiving a signal from a wireless gauge down in the well. BP also said Wednesday that it had lowered a containment box known as a “top hat” to the sea floor. A far smaller device than a containment dome that failed over the weekend, it could be connected by the end of the week, the company said.
In Washington, a House subcommittee interrogated executives of the four companies at the heart of the accident: BP, which owns the well; Transocean, which provided the drilling rig and much of the manpower; Halliburton, which provided the cement to seal the well; and Cameron, which provided the blowout preventer. “This catastrophe appears to have been caused by a calamitous series of equipment and operational failures,” said Representative Henry A. Waxman, Democrat of California, the chairman of the Energy and Commerce Committee. “If the largest oil and oil service companies in the world had been more careful, 11 lives might have been saved and our coastlines protected.”
Information released by the committee was contradictory on a key point: whether the well had failed a pressure test hours before the blowout. Mr. Waxman said, in an introductory statement, that a test conducted in the afternoon appeared to show that the well was not tightly sealed and that natural gas was flowing into it. But on Tuesday, he said, BP lawyers told the committee that additional tests had been performed that day and that at 8 p.m., two hours before the explosion, company officials determined that well operations could proceed.
Those operations included removing a heavy substance called drilling mud from the pipe leading down to the well, and replacing it with sea water, which is lighter and would have made a blowout more likely if the well were not properly sealed.
For the second day, officials from the Coast Guard and Minerals Management Service continued grilling their own officials at a public hearing about the explosion on the Deepwater Horizon.
On Wednesday, the Obama administration proposed a $118 million package of actions to combat the Gulf oil spill, most of it to be paid for by BP, including unemployment benefits for fishermen put out of work and food aid for those hurt by the spill.
14 May 2010
Get on with it
Henry Fountain and Matthew Wald have an article in The New York Times about the Gulf leak and BP's attempts to fix it:
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