The blowout preventer that failed on a BP well last year was four years overdue for maintenance under driller Transocean Ltd.’s internal guidelines, a U.S. regulator said.
The Deepwater Horizon’s blowout preventer had not been disassembled and refurbished since the rig was commissioned in 2001, said Jason Mathews of the U.S. Bureau of Ocean Energy Management, Regulation and Enforcement during an investigative hearing in Metairie, La.
Under Transocean’s own rules, there should have been an overhaul of the blowout preventer no later than the summer of 2006, Mathews said.
The preventer is a 300-ton stack of valves and pipes designed to stop an oil well from surging out of control.
In the Deepwater Horizon incident, the blowout preventer’s blades failed to sever and seal the pipe from BP’s Macondo well during the April 2010 disaster that killed 11 rig workers, sank the vessel, and spewed enough crude into the sea to fill two supertankers, according to a study commissioned by a joint US Coast Guard-Interior Department panel. Mathews is one of eight members of the panel.
The blowout preventer wasn’t in need of an overhaul, Michael Fry, a Transocean manager who oversees subsea equipment used on all of the company’s Gulf of Mexico rigs, told the panel.
“If it’s not found to be outside its operating tolerances, that piece of equipment stays in service,’’ Fry said.
A study of the blowout preventer, carried out by Det Norske Veritas, concluded a lack of maintenance work was not a factor in the failure of the blades to crimp the pipe. Cameron International Corp., based in Houston, made the blowout preventer used by the Deepwater Horizon.