House Democrats accused companies involved with the Deepwater Horizon rig disaster of knowing about equipment problems but proceeding with well operations anyway.
House investigators also revealed that a fail-safe device known as the blowout preventer had a significant leak in a key hydraulic system and other problems.
"The more I learn about this accident, the more concerned I become," said Energy and Commerce Chairman Henry Waxman (D-Calif.).
The catastrophe appears to have been caused by equipment and operational failures and might have been averted if the companies had been more careful, Waxman said. The committee has already received more than 100,000 pages of documents for its investigation of the April 20 rig explosion that killed 11 workers and has spilled millions of gallons of crude in the Gulf of Mexico.
Waxman said Halliburton Co. says it had secured the well through a cementing process and that the well had passed a key pressure test, but he added, "But we now know this is an incomplete account." The well did pass positive pressure tests but did not pass crucial negative pressure tests, he said.
Waxman said James Dupree, the BP senior vice president for the Gulf of Mexico, said the well did not pass a "negative pressure" test, which tests whether any gas is leaking into the well through the cement or casing.
Dupree told committee staff that results of a first test were "not satisfactory" and "inconclusive" and that significant pressure discrepancies were recorded, Waxman said. A second test found similar results.
Dupree told the staff he believed the well blew moments after the second pressure test, Waxman said. But BP lawyers yesterday told the committee that further investigation has found that additional pressure tests were taken that allowed company officials to determine that the tests could end and well operations could proceed.
"This confusion among BP officials appears to echo confusion on the rig," Waxman said, adding that information reviewed by the committee describes an internal debate between Transocean Ltd. and BP on how to proceed.
Lamar McKay, chairman and president of BP America, agreed that there were "anomalous" pressure tests that "could have raised concerns about well control" and said it will be crucial to investigate that fact and understand what happened. "We'll have to tear that apart piece by piece," he said.
Steven Newman, CEO of Transocean, said the pressure discrepancy "would lead to a conclusion there was something happening in the wellbore that should not be happening."
Rep. Bart Stupak (D-Mich.), chairman of the Oversight and Investigations Subcommittee, also said the panel's investigation found at least four significant problems with the blowout preventer, the fail-safe device on the Deepwater Horizon rig that failed.
The blowout preventer had a significant leak in a key hydraulic system and was modified in unexpected ways, Stupak said. He added that emergency controls on the device may have failed and that blowout preventers are not powerful enough to cut through joints in drill pipe but only through the body of the pipe.
He questioned whether BP and its partners fulfilled their safety obligations. "The safety of its entire operations rested on the performance of a leaking, modified and defective blowout preventer," Stupak said.
Stupak also cited a Transocean document from 2001, when it bought the blowout preventer from Cameron International Corp. The document said there are 260 separate "failure modes" that could require pulling of the device. "How can a device that has 260 failure modes be considered fail-safe?" he asked.
McKay also said the investigation must focus on why the blowout preventer, a device from Transocean, did not work.
But Newman told the committee that the blowout preventers, or BOPs, were not the main cause of the disaster. At the time of the explosion, the drilling process was complete, the well had been sealed and the BOPs would have been removed within a few days.
"The one thing we do know is that on the evening of April 20, there was a sudden, catastrophic failure of the cement, the casing, or both," he said. "Without a disastrous failure of one of those elements, the explosion could not have occurred."
Newman also said the modifications to the blowout preventer were agreed to five years ago in a compact between BP and Transocean. "It was done at BP's request and BP's expense," he said.
But Tim Probert, chief health, safety and environmental officer at Halliburton, said it is premature to say a catastrophic failure of the cement or casing caused the disaster and said that if the blowout preventer had worked, the explosion would not have occurred.
Republican blames regulators
Ranking member Joe Barton (R-Texas) said the accident should not be used as an "excuse" not to develop what is likely the largest domestic energy resource yet to be tapped.
While the investigation shows "there was in all probability shoddy maintenance ... mislabeled components" and other problems, Barton added that corrective measures can be taken to prevent another disaster from happening again.
"But what we should not do is make a decision to fence off the outer continental shelf," he said. "I want to solve that problem, and I want to move forward."
Rep. Michael Burgess (R-Texas), ranking member of the Oversight and Investigations Subcommittee, criticized the hearing as "asymmetric oversight" because no documents had been obtained from the Obama administration or federal agencies responsible for oversight. Interior Secretary Ken Salazar should have testified today, Burgess said.
The application for drilling filed for the Deepwater Horizon rig raised some red flags, Burgess said. While he would not blame the companies for trying to save money when filing plans, the fact that federal regulators did not require better mitigation plans "is where the problem exists, in my mind."
"Why did the federal regulators just simply rubber-stamp this?" Burgess asked. "It just seems like more care should have been delivered up front."
Rep. Edward Markey (D-Mass.), who chairs the Energy Subcommittee, said it is "hard to have confidence in BP" because it called the chance of a major spill unlikely and said it never thought the rig could sink.
He also derided a method known as a "junk shot" that BP plans to use to try to stop the leak by injecting debris, possibly including rubber and sliced-up golf balls, into the blowout preventer.
"When we heard the best minds were on the case, we expected MIT, not the PGA," Markey said.