WASHINGTON (Reuters) - The failure of the underwater blowout preventer that led to the massive BP oil spill in the Gulf of Mexico was caused by the inability of the blind shear rams to close and seal the leaking well, the U.S. government said on Wednesday.
"The primary cause of failure was identified as the (blind shearing rams) failing to close completely and seal the well due to a portion of drill pipe becoming trapped between the ram blocks," according to a report commissioned by the Interior Department and Department of Homeland Security.
The blowout preventer used with the BP <:BP.LO:>well was manufactured by Cameron International.
The shear rams were unable to move the entire pipe cross section into the shearing surfaces of the blades, the report said. The drill pipe was also deformed and buckled.
"Once buckling occurred the (blind shearing rams) would not have been able to completely close and seal the well. The buckling most likely occurred on loss of well control," the report said.
The report recommended the oil industry study ways to make sure shear rams can completely cut pipes regardless of their position within the wellbore and seal a well.
Those industry findings should be incorporated in the design of future blowout preventers and modifications to existing ones, the report said.
(Reporting by Tom Doggett and Ayesha Rascoe;editing by Sofina Mirza-Reid)