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BP spill investigation focuses on seven control mechanisms

Paula Dittrick
OGJ Senior Staff Writer

HOUSTON, May 25 -- BP PLC has identified seven control mechanisms in its internal review into causes behind Transocean Ltd.’s Deepwater Horizon semisubmersible fire and the resulting deepwater Macondo well oil and gas spill in the Gulf of Mexico.

BP called its investigation “a fact-finding effort that has not reached final conclusions,” but identified issues for further inquiry. In a news release late May 24, BP said it shared its report with the US Department of the Interior and will share it with other regulatory investigations into the Apr. 20 accident that left 11 crew members missing and presumed dead.

“I understand people want a simple answer about why this happened and who is to blame,” said BP Group Chief Executive Tony Hayward. “The honest truth is that this is a complex accident, caused by an unprecedented combination of failures. A number of companies are involved, including BP, and it is simply too early—and not up to us—to say who is at fault.” BP operates the Macondo well.

The internal investigation’s initial report said that much more work is needed, including full examinations of the failed blowout preventer (BOP), the wellhead, and the rig itself—all currently on the seabed in 5,000 ft of water, BP said.

The company’s Group Safety and Operations launched the investigation on Apr. 21.

Preliminary findings showed “the failure of a number of processes, systems, and equipment,” contributed to the accident. BP named multiple control mechanisms, including procedures and equipment that should have prevented the accident or reduced the flow from Macondo well on Mississippi Canyon Block 252.

In a summary of its findings so far, BP said its internal investigation focused on the following seven mechanisms:

• Cement that seals the reservoir from the well.

• Casing system that seals the wellbore.

• Pressure tests to confirm the well is sealed.

• Execution of procedures to detect and control hydrocarbons in the well, including the use of the BOP.

• BOP Emergency Disconnect System, which can be activated by pushing a button at multiple locations on the rig.

• Automatic closure of the BOP after its connection is lost with the rig.

• Features in the BOP to allow remotely operated vehicles (ROVs) to close the BOP and thereby seal the well at the seabed after a blowout.

The report comes as the US Coast Guard and the Minerals Management Service resume public hearings in a joint investigation. Those hearings are scheduled for May 26-29 in Louisiana. Scheduled witnesses include executives from BP and Transocean.

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