By Russell Gold
Federal investigators probing the 2010 Deepwater Horizon
disaster say a critical piece of safety equipment helped trigger
the worst offshore oil spill in U.S. history.
The report by the Chemical Safety Board, an independent
investigative arm of the federal government, renews questions about
the effectiveness of blowout preventers, giant sets of valves that
are supposed to seal off an oil well in an emergency.
The draft report concludes that the pipe running from the subsea
oil well to the drilling rig through the blowout preventer, or BOP,
buckled around the time a surge of natural gas from the well
ignited, causing an explosion which killed 11 crew members.
The pipe was damaged in such a way that the blowout preventer
couldn't cut it and seal it off, the board said. The buckling
occurred because of big differences in pressure inside and outside
the pipe, which ran through about 5,000 feet of water.
The blowout preventer itself punctured the pipe, the board said,
allowing oil to start leaking into the Gulf of Mexico close to the
seabed. About five million barrels of oil flowed into the gulf
before the well was closed off, 87 days later.
"The pipe buckling--unlikely to be detected by the drilling
crew--could render the BOP inoperable in an emergency," said Mary
Beth Mulcahy, who led the technical analysis for the board. "This
hazard could impact even the best offshore companies, those who are
maintaining their blowout preventers and other equipment to a high
standard."
The American Petroleum Institute, the energy industry's trade
group, criticized the report, saying it "appears to omit
significant facts and ignores the tremendous strides made to
enhance the safety of offshore operations." The federal government
expects to issue a new rule later this year on blowout
preventers.
BP PLC, which owned the well about 50 miles off the coast of
Louisiana, said Transocean Ltd., which owned the drilling rig and
the blowout preventer, "failed to, among other things, properly
maintain the BOP and control the well."
Transocean said the report "confirms that the Deepwater Horizon
BOP had been tested successfully in accordance with regulatory
requirements and activated as intended at the time of the
incident."
Cameron International Corp., which made the device, declined to
comment.
The report is in broad agreement with previous investigations
about what initially caused the disaster, which began on April 20,
2010, as the Deepwater Horizon crew tried to put a temporary plug
into an oil well deep underwater. Rig workers made a grievous
mistake when they tested the cement in the well and, despite
anomalous readings, decided it was stable, the report says.
Some prior probes into the accident have said that faulty
maintenance and defective equipment kept the crew from activating
the BOP at the time of the accident, and that it was triggered
remotely two days later.
The new report says it was in fact activated automatically in
the minutes after the explosion aboard the rig.The report also
suggests that early emergency steps taken by the crew had brought
the gushing well under control before the BOP's shearing rams were
triggered.
Write to Russell Gold at russell.gold@wsj.com
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