Energy Source

BP has given its most detailed statement yet of the likely causes of the Deepwater Horizon rig explosion on April 20, which led to its huge oil spill in the Gulf of Mexico.

In recent weeks, BP has shown a tendency to try to pass the buck, trying to put the blame on Transocean, which owned the rig, just as Transocean has attempted to do the same to BP and to Halliburton, which was the sub-contractor for cementing the well. That attempt to evade responsibility has provoked some strong criticism of BP, however, and this latest statement shows more readiness to accept at least a share of the blame.

BP was responsible for critical decisions on the Deepwater Horizon drilling rig, its contractors have said, pointing the finger at the British company for its role in the disaster that killed 11 men and created an oil slick the size of Florida in the Gulf of Mexico.

In prepared testimonies ahead of a Senate hearing on Tuesday, executives from Transocean, which owned the rig, and Halliburton, which was responsible for cementing the well to secure it after it had been drilled, both described BP’s role in designing and overseeing the project, and in making key decisions about technical details.

This is a rather different picture of the working practices on the rig from the account often presented by BP.

Piecing together the causes of the Deepwater Horizon disaster will take months. Exactly what happened on the night of April 20 may never be known: some of the key equipment may never be recovered from the sea bed, and the 11 men who died in the blast appear to have been the ones closest to the explosion, because they were working on the drill floor when it happened.

The investigations mounted by BP, Transocean and the US authorities will be huge forensic exercises, akin to the task of trying to understand an air crash in mid-ocean.

From accounts provided by survivors, the companies involved and industry experts, this explains what we think we now know about the Deepwater Horizon explosion, and what the recovery of the blowout preventer could reveal.