BP Oil Spill: Pipe Piece Caused Blowout Preventer Failure

NEW ORLEANS (AP) -- A federal probe has found that a trapped piece of drill pipe prevented a key failsafe device from properly sealing off the blown oil well that caused last year's massive Gulf oil spill, according to a report released Wednesday.

The report of more than 551 pages said the device, known as a blowout preventer, failed to work properly because the piece of drill pipe kept its blind shear rams from closing and sealing the well. Shear rams are components in a blowout preventer that cut, or shear, through drill pipe and form a seal against well pressure.

The Norwegian firm that the government hired to test the blowout preventer said the way the drill pipe was positioned within the wellbore caused it to buckle and bow when the well lost control, impeding the rams.

The lengthy report does not assign blame to any one company, but does find fault with the functionality and design of the blowout preventer. The device was made by Cameron and maintained by Transocean Ltd.

Blowout preventers sit at the wellhead of exploratory wells and are supposed to lock in place to prevent a spill in case of an explosion.

The 300-ton device that was used with BP's Macondo well was raised from the seafloor Sept 4. Testing began at a NASA facility in New Orleans in November.