Whilst Transocean and Halliburton were involved (it was transoceans rig that blew up and Halliburton cemented the well) it appears at this stage as if BP is mostly to blame. Halliburton raise the discrepancies in the data to say something was not right. BP basically told them to shut up and carry on. And the rest is history... including, sadly, 11 people's lives.
BP has now publicly accepted the blame, which I doubt they would do if they thought there was even a chance of escaping a guilty verdict.
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May 12 (Bloomberg) ? A Gulf of Mexico oil well failed a pressure test hours before a drilling rig exploded last month, an executive for well owner BP Plc told the U.S. House Energy Committee that?s investigating the incident.
Such pressure tests are aimed at ensuring the integrity of cement poured into the well to keep out natural gas, said Committee Chairman Henry Waxman, a California Democrat, citing a report to the panel from James Dupree, BP senior vice president for the Gulf. The tests before the April 20 blast showed ?discrepancies? in pressure levels, Waxman said. ?There was something happening in the well bore that shouldn?t be happening,? Steven L. Newman, chief executive officer of rig owner Transocean Ltd., said today in testimony.
The committee is investigating the explosion that killed 11 workers, sank Transocean?s $365 million Deepwater Horizon rig, and triggered a spill that threatens the Gulf Coast from Louisiana to Florida with more than 3 million gallons of oil. The panel also is probing equipment meant to prevent spills at deepwater wells and whether human error played a role.
?BP, one of the largest oil companies, assured Congress and the public that it could operate safely in deep water and that a major oil spill was next to impossible,? Waxman said. ?We now know those assurances were wrong.?
At least eight congressional panels have set hearings on the incident. Executives from BP, Transocean and Halliburton Co. testified yesterday before the Senate Energy and Natural Resources and the Environment and Public Works committees. The same executives are appearing before the House panel today.
Hydraulic Leak
The House committee staff found that a device to prevent spills, the blowout preventer, had a hydraulic system leak, said Representative Bart Stupak, a Michigan Democrat. Timothy Probert, president of global business lines at Houston-based Halliburton, told a Senate panel yesterday and the House committee today that had the device not failed, the ?catastrophe? might have been avoided.
?The blowout preventer apparently had a significant leak,? Stupak said. ?This leak was found in the hydraulic system that provides emergency power to the shear rams, which are the devices that are supposed to cut the drill pipe and seal the well.?
The leak was found after the explosion by remote-controlled robots attempting to activate the device and stanch the estimated 5,000 barrels of oil a day flowing into the Gulf. The blowout preventer also had been modified in ?unexpected ways,? prior to the blast, and may not have been strong enough to cut the drill pipe and shut the well, Stupak said.
?Serious Questions?
?BP promised to make safety its number one priority,? Stupak said. ?This hearing will raise serious questions about whether BP and its partners fulfilled this commitment. The safety of its entire operations rested on the performance of a leaking and apparently defective blowout preventer.?
The blowout preventers made by Cameron International Corp. will shear and seal drill pipe and won?t shear and seal the casing, President Jack Moore said today in testimony.
Halliburton completed cementing the well 5,000 feet below the surface at 12:35 a.m. on the day of the explosion, Waxman said. A pressure test was conducted about 5 p.m. to determine if gas was leaking into the well.
Dupree told committee staff members on May 10 that the test was ?not satisfactory,? and was ?inconclusive,? because pressure discrepancies were recorded. Waxman said.
Second Test
A second test also produced results that weren?t satisfactory, Waxman said. It showed pressure on the drill pipe, running from the rig deep into the well, was 1,400 pounds per square inch. Zero pressure was observed on so-called kill and choke lines, which run from the rig platform to the sea bed.
Pressures should be the same on all three lines, Dupree told the committee staff. The results could signal that gas was causing pressure to build inside the well, Dupree told staff, according to Waxman. ?The significance of the discrepancy between the two pressures would lead to a conclusion? something was happening in the well bore, Transocean?s Newman said today.
Halliburton?s Probert said it was premature to conclude ?a catastrophic failure of the casing of cement? was the cause of the blast.
Dupree told staff that he believed the well exploded moments after the second pressure test, Waxman said. That contradicts an account from BP?s lawyers that further well tests were conducted about 8 p.m. The result of that test led BP to proceed with well operations, Waxman said.
Transocean, BP Debate
?Information reviewed by the committee describes an internal debate between Transocean and BP personnel about how to proceed,? Waxman said. ?What we do know is that shortly before 10 p.m., just two hours after well operations apparently resumed, gas surged from the well up the riser and the rig exploded in a fireball.?
BP lowered a small ?top hat? oil-containment dome to the floor of the Gulf today, advancing a second attempt to funnel oil from the leaking well to a ship on the surface. The unit must be connected by pipes to the ship before installation and is still expected to be working by the end of the week, Mark Proegler, a spokesman for the London-based company, said in an interview today