The historic BP oil well explosion in April 2010 was not supposed to be so bad. If things had gone as planned, the offshore drilling rig’s last defense — a deep-sea mechanism called a “blowout preventer” — would have kicked in, sealing the drill pipe and short-circuiting the explosion, potentially preventing 11 deaths and 5 million barrels of crude oil spilling into the Gulf of Mexico.
But for reasons unknown, the blowout preventer malfunctioned, part of an array of errors that left behind the largest accidental marine oil spill in the history of the petroleum industry, according to a U.S. Chemical Safety Board report released Thursday.
That report also said the same equipment is still widely-used in offshore drilling, and more needs to be done to make it safer.
“Although both regulators and the industry itself have made significant progress since the 2010 calamity, more must be done to ensure the correct functioning of blowout preventers and other safety-critical elements that protect workers and the environment from major offshore accidents,” CSB Chairman Rafael Moure-Eraso said in a statement.
Like other reports that have been released on the disaster, the CSB’s two-volume draft report pointed to multiple causes, but placed a deeper focus on the blowout preventer — a “last line of defense” against runaway wells used on both offshore and onshore operations. According to the report, an emergency device within the blowout preventer called a “blind shear ram” activated as planned, but didn’t seal the pipe like it was supposed to. As Clifford Krauss explains in the New York Times:
The shear ram did not seal the well drill pipe; instead, it punctured the pipe and sent oil and gas gushing to the surface. The study found that the drill pipe had buckled under the tremendous pressure of the oil and gas rising from the well from the initial blowout, while previous studies concluded that the pipe buckled days after the initial explosion.
The report concluded that the issues with the blowout preventer on BP’s well were not exclusive to BP, and represented a problem that needs to be addressed across the drilling industry. The American Petroleum Institute (API), the U.S. trade association for both upstream and downstream petroleum industry, should for instance increase testing requirements for blowout preventers, the report said.
“Although there have been regulatory improvements since the accident, the effective management of safety-critical elements has yet to be established,” CSB’s leader of the investigation, Cheryl MacKenzie, said in a statement. “This results in potential safety gaps in U.S. offshore operations and leaves open the possibility of another similar catastrophic accident.”
In other words, “It could happen again,” MacKenzie told a group in in downtown Houston.
Of course, the blowout preventer was not the only thing that has been cited as a cause of the historic Gulf spill. In 2012, the CSB concluded that “BP applied lesser process safety standards” to contracted drilling rigs and that the company “dropped the ball on major accident hazards.” Two BP supervisors who were on board the Deepwater Horizon rig are also facing manslaughter charges for the 11 workers killed, as prosecutors have accused them of mishandling an important safety test and failing to report abnormally high pressure readings that attorneys say were were obvious signs of an impending disaster.