Lawmakers on a House subcommittee probing the causes of the Deepwater Horizon rig explosion said Wednesday they had found multiple deficiencies in a key system designed to be the last line of defense against a blowout.
Rep. Bart Stupak (D-Mich.), chairman of the Energy and Commerce Oversight and Investigations subpanel, which opened its hearing Wednesday, said there were at least “four significant problems” with the blowout preventer. The system is supposed to seal off a well in an emergency and prevent unwanted leaks.
“The safety of [BP’s] entire operation rested on the performance of a leaking, modified and defective blowout preventer,” Stupak said.
Stupak outlined other issues as well.
The preventer had been modified and a test ram, which is not intended to pinch the pipe in case of an emergency, had been improperly wired to a control panel BP officials tried to use to shut off the spill.
Meanwhile, blowout preventers in general are not powerful enough to cut through threaded joints that link different sections of drill pipe. That leaves around 10 percent of the pipe that the preventer would be unable to shear through.
Lastly, emergency systems designed to engage the blowout preventer appear to have failed.
Timothy Probert, an executive with Halliburton, said if the blowout preventer had worked, “the accident would not have happened.”
BP Chairman and President Lamar McKay and executives from Transocean, which owned the drilling rig, and Cameron International, which built a system designed as a last line of defense against oil blowouts, also testified.
Rep. Henry Waxman (D-Calif.), the chairman of the House Energy and Commerce Committee, sharply criticized the companies involved in the accident.
“This catastrophe appears to have been caused by a calamitous series of equipment and operational failures,” Waxman said.
Waxman focused on a critical pressure test prior to the blast on the Deepwater Horizon rig. Workers on the rig conducted the test to see if a cement cap inside the well designed to keep explosive gas from leaking up was working.
Waxman said James Dupree, BP senior vice president for the Gulf of Mexico, told House investigators that cement poured into the drill by Halliburton was given 16.5 hours to set. Then fluid pressure inside the well was reduced to observe whether gas was still getting through, according to Waxman.
Waxman said Dupree said the first test was “not satisfactory” and “inconclusive” because of “significant pressure discrepancies.”
A second test also found starkly different pressure readings within the drill system, Waxman said Dupree told investigators. The test measures pressure at three points: inside the drill that is under the sea floor and on “choke” and “kill” lines that run from the drilling rig to the blowout preventer near the well hole.
The drill had pressure readings of 1,400 pounds per square inch (psi). The choke and kills lines had 0 psi readings.
Executives at oil companies involved with the drilling operation who testified Wednesday said the different readings would be cause for concern.
The discrepancies indicate “something is happening in the well bore that shouldn’t be happening,” said Steven Newman, CEO of Transocean.
Waxman said Dupree told the committee that he believed the second test took place just moments prior to the blast, but Waxman said there remained confusion about when the tests were conducted.
A counsel for BP told the committee on Tuesday subsequent tests eased concerns and “at 8 p.m. company officials determined that the additional results justified ending the test and proceeding with well operations,” Waxman said.
The explosion happened around two hours later.
Halliburton’s Probert said it was premature to pin the blame on the cement or casing inside the well as a cause of the “catastrophe.” Halliburton poured the cement into the well hole.