WASHINGTON — A top BP worker who was aboard the Deepwater Horizon in the hours leading up to the explosion declined to testify in front of a federal panel investigating the deadly oil rig blowout, telling the U.S Coast Guard he was invoking his constitutional right to avoid self-incrimination.
The move Wednesday by BP's Robert Kaluza raises the possibility of criminal liability in the April 20 explosion that killed 11 and five weeks later continues to spew hundreds of thousands of gallons of oil into the Gulf of Mexico each day.
Wednesday's government hearing in Louisiana, however, failed to determine why — despite unusual pressure and fluid readings on the rig — a BP official decided on the day of the explosion to proceed with removing heavy drilling fluid from the well and replacing it with lighter-weight seawater that was unable to prevent gas from surging to the surface and exploding.
Employees and experts testified that in the hours before the explosion, they witnessed a power struggle over that decision — the kind of argument common among the different parties that lease and run complicated offshore drilling operations, but one that this time, had deadly consequences.
One employee who worked for the rig owner, Transocean, was so mad after the fight that he warned they'd be relying on the rig's blowout preventer if they proceeded the way BP wanted.
"He pretty much grumbled, 'Well, I guess that's what we have those pinchers for,'" the rig's chief mechanic, Doug Brown, said of Jimmy Harrell, the top Transocean official on the rig. "Pinchers" was likely Harrell's reference to the shear rams in the blowout preventers, the final means of stopping an explosion.
BP, though, had ultimate authority over drilling decisions, and Brown said in sworn testimony Wednesday that the BP official at the meeting stood up and said, "This is how it's going to be."
The BP official, a "company man" in industry parlance, would have been the top decision-maker on the rig, although his role may have been complicated by having a number of higher-ranking BP officials on hand to celebrate the Deepwater Horizon's safety record.
Investigators asked Brown whether he knew the name of the BP official who made the decision, but he couldn't recall it and didn't know whether it was Kaluza.
Kaluza's lawyers, Shaun Clarke and David Gerger, called him "a dedicated, hard-working, conscientious man" who's worked in oil fields around the country for 35 years. He "did no wrong on the Deepwater Horizon," they said in a statement.
A BP employee named Donald Vidrine, who's been identified as one of the company men, was on the original witness list for the multi-day hearings, but is no longer scheduled to testify due to an undisclosed medical condition. Harrell is on the witness list for Thursday.
BP wouldn't identify what role Kaluza and Vidrine had on the Deepwater Horizon. Company spokesman Graham MacEwen said that any decision about whether to testify to the joint Coast Guard and Minerals Management Service inquiry would be up to those employees and their lawyers.
The Justice Department hasn't confirmed a criminal investigation, but Congress has called for one, and federal investigators have asked the rig owner, Transocean, to safeguard potential evidence.
The company men have a key role on a drilling rig, said Carl Smith, a former U.S. Coast Guard captain and expert witness, who testified Wednesday.
"Their emphasis is they're trying to drill to make money for their company, so their primary interest is to make progress on the well," he said. "So, you're always going to have a conflict between the people who are representing the owner's of the rig and the people who are renting it because the people who are renting it want to go faster and drill, and the people who are operating the rig want to maintain the integrity of the rig, which is a natural conflict."
It's also clear that BP was in charge, said Houston attorney Kurt Arnold, who represents 15 Deepwater Horizon workers, and the family of one who died.
"Whether or not to move this equipment to X,Y,Z place is a lower-level crane operator decision that Transocean makes, but what to do in the actual drilling process comes down to the client." Arnold said. "The client always is informed, the client has final say. BP was the client. BP had the rights to drill. They hired these other companies."
Wednesday's hearing continued to provide more detail about what happened in the hours leading up to the explosion, but little explanation for why BP ignored so many warnings and went forward with the controversial decision to remove drilling mud when it did.
On the morning of the explosion, crews had finished injecting cement into the well to strengthen the sides and protect the pipe. At about 5 p.m., pressure tests that revealed something was wrong with the newly cemented well.
It passed one set of so-called positive pressure tests in which fluids were injected into the well to increase pressure to monitor whether the well remained stable. However, it failed a negative pressure test, in which fluid inside the well is reduced to see whether gas leaks into the well through the cement or casing.
Despite the pressure problems, BP decided at about 8 p.m. to resume extracting mud, but the pressure in part of the well spiked, gas escaped and the rig exploded. The decision to proceed regardless may have been a "fundamental mistake," BP's own internal investigators told House of Representatives investigators this week. Crews noticed unusual pressure and fluid readings that should have alerted them not to remove the mud from the well, BP acknowledged.
"That's something you learn at well-control school," Smith told the panel on Wednesday in Louisiana. "If you're circulating fluid, you need to monitor how much is going in and how much is coming out. If you got more fluid out than in, it's an indicator that something's going on."
Wednesday on Capitol Hill, Interior Secretary Ken Salazar repeatedly told the House Natural Resources Committee that the many of the problems within MMS were those of the "previous administration's" term.
Committee members asked few questions about the cause of the accident, however, or about what oversight role the now-reorganized agency had in ensuring that such blowouts don't occur. When asked about inspectors and tests done aboard the Deepwater Horizon, the head of the MMS, Elizabeth Birnbaum, declined to comment, saying the Interior Department's investigation is ongoing.
(Bolstad and Taylor reported from Washington. Goodman, of the Miami Herald, reported from Kenner, La. Mark Washburn of The Charlotte Observer in Charlotte and Lauren French in Washington contributed to this article.)