Blowout preventer not tested to shear pipe

The blowout preventer that failed to stop last year’s Gulf of Mexico oil spill hadn’t been tested to see if it could cut through a bent drill pipe, said a senior official of the company that made the device.

04/26/2011


The blowout preventer that failed to stop last year’s Gulf of Mexico oil spill hadn’t been tested to see if it could cut through a bent drill pipe, said a senior official of the company that made the device.

The firm hired by the government to examine the 300-ton device after they brought it up from the seafloor concluded the blind shear rams couldn’t pinch the well shut by cutting through the drill pipe. That’s because the pipe was off center. The firm faulted the design of the Cameron-made blowout preventer.

Cameron vice president David McWhorter told a federal investigative panel he couldn’t say if the company designed the device to cut through a bent drill pipe. He said it did not undergo testing for that possibility before the disaster.

“I am not going to hazard an opinion,” said McWhorter, who works in Cameron’s division that handles engineering and quality for drilling systems.

The testimony wrapped up the seventh series of hearings before the joint U.S. Coast Guard-Bureau of Ocean Energy Management Regulation and Enforcement panel, which is investigating the causes of the Deepwater Horizon rig explosion off Louisiana last April 20. The blast killed 11 workers and led to the worst offshore oil spill in U.S. history.

The panel should release a preliminary statement within the next few weeks and will issues a full report in July.

In earlier testimony, Ralph Linenberger, a BP consultant hired to monitor the blowout preventer examination on behalf of the company, questioned the findings of testing firm Det Norske Veritas. Among other things, he said he did not see evidence the drill pipe had buckled, as DNV concluded it had.

“It looked fairly straight to me,” Linenberger said.

He also said DNV did not conduct any substantive testing that would look at the possibility of maintenance of the blowout preventer being a potential factor in the device’s failure.

Transocean owned the rig that exploded and was responsible for maintaining the blowout preventer. BP was leasing the rig from Transocean and owned the undersea well that blew out.



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