A faulty blowout preventer and weaknesses in how firms analyse potential hazards offshore contributed to BP’s deadly Gulf of Mexico oil spill more than four years ago, the US Chemical Safety Board (CSB) said yesterday.
The CSB, which has no enforcement authority but can recommend safer practices, routinely probes accidents at chemical plants and refineries.
It did not examine all aspects of the Deepwater Horizon Macondo blowout and explosion that killed 11 men and unleashed more than 4million barrels of oil into the Gulf in 2010.
Rather than re-examine issues already covered by other probes, including those by the US Coast Guard and a commission appointed by President Barack Obama, it studied equipment and hazardous materials operations and safety management.
BP spokesman Geoff Morrell said the core findings were consistent with other probes that found the disaster stemmed from multiple causes and involving multiple parties.
The CSB concluded that the blowout preventer failed because miswired control systems would have prevented it from sealing the blown-out well.
A blowout preventer is a multi-tonne stack of valves and pipes that sits atop deepwater wells to stop oil and gas from gushing upward in an accident.
The CSB said different pressures inside the drillpipe and the area between the pipe and the well moved Macondo’s blowout preventer off-centre, so a key piece of equipment called the shear ram could not slice through the pipe to seal the well.
Other probes have found that explosions aboard Transocean’s Deepwater Horizon rig moved the pipe.