Blowout preventer manufacturer questions Deepwater Horizon forensic report


A top executive at the company that built the Deepwater Horizon’s blowout preventer expressed major doubts Friday about recent theories of why the massive subsea device failed to shut off BP’s blown out Gulf oil well last year.

David McWhorter, Cameron International’s vice president for engineering and quality control, spent several months helping advise the forensic examiners who were hired by the government to inspect his company’s failed BOP, but he said during testimony before a federal investigative panel in Metairie on Friday that he had major questions about those forensic findings.

Those findings were released two weeks ago by Det Norske Veritas, a Norwegian company hired by federal investigators to produce what was essentially a coroner’s report to help government agencies figure out what stopped the BOP from shutting off the worst oil gusher in American history.

Det Norske Veritas concluded that oil and gas shooting up through a 5.5-inch drill pipe at extremely high pressures caused the pipe to bend, knocking it off-center in the middle of the BOP. Without a centered pipe, the device couldn’t use its powerful slicing rams to cut and seal the pipe shut.

The implication of those findings is that the blowout preventer wasn’t designed by Cameron to handle such intense emergency conditions. Cameron said it built the BOP to industry standards, but those standards never conceived of a bowed pipe. And standardized tests of BOPs never included a check to see whether the rams could cut off-center pipe.

But under questioning earlier this week, Det Norske Veritas officials acknowledged that they had no physical evidence of the pipe bending and that the elastic bowing of the pipe was simply their theory of what happened based on modeling.

Seizing on that, McWhorter faulted the examiners for not presenting several other things that he believes could have gone wrong to prevent the rams from cutting properly — things that wouldn’t have required the pipe to bend and would have resulted from poor maintenance of the blowout preventer’s components by the rig’s owner, Transocean.

The Cameron executive questioned whether there could have been enough pressure to buckle the pipe, which by Det Norske Veritas’ own calculations, would have required an incredible 113,000 pounds per square inch of force.

McWhorter said the examiners also ignored the possibility that the critical blind shear rams didn’t work because there simply wasn’t enough power to get them to close fully. He said a normal level of 1,500 psi might have initially triggered the rams instead of the much higher triggering pressures that should have been employed in an emergency.

“If that happened, it would not have been enough force to cut the pipe (even if centered),” McWhorter said. “It’s possible then that the pipe was only dented, not sheared all the way through.”

He said hydraulic controls might also have simply “not been up to the game that day.” And he noted that the “deadman” function that is supposed to automatically close the rams and disconnect the rig from the well when hydraulics, electricity and communications are all lost can be manually armed or disarmed. He suggested it wouldn’t have worked if it wasn’t armed when the blowout happened, but he didn’t know whether it was or was not.

There has been no testimony or investigative findings indicating whether the “deadman” was armed on the Deepwater Horizon that day.

Investigators did find that a solenoid valve that helps trigger emergency closure of the BOP’s rams worked only intermittently during later testing. That, McWhorter said, also could have yielded a partial closure of the blind shear rams even if the pipe had been properly centered.

It’s been difficult for investigators to get a clear picture of why the “fail-safe” mechanisms in the BOP didn’t work, or, for that matter, when various functions of the BOP activated. Specialists spent two weeks after the explosions trying to get rams and valves to work using remote-controlled submarines, which meant the blowout preventer was not in the same position as it was on April 20, by the time it was brought to the surface in September.

Also, people opened and closed valves and rams in the BOP when it was first brought to the surface and was still on a ship. That again mo

Stuart H. Smith is an attorney based in New Orleans fighting major oil companies and other polluters.
Cooper Law Firm

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