Oil giant BP is focusing on two key areas around the blown wellhead as it probes the cause of the unchecked Gulf of Mexico oil spill and has started to brief federal authorities on the first results of its internal investigation.
BP PLC said in a release late Monday that its probe has not reached a final conclusion. But it said multiple control mechanisms should have prevented the accident that started with an oil rig explosion April 20.
The largest oil and gas producer in the Gulf listed seven mechanisms where its hunt for a cause is focused. Four of those involve the blowout preventer, a massive piece of machinery that sits atop the well head and is supposed to act as a safety device of last resort. The other three areas of investigation involve the cementing and casing of the well head.
Those points could involve one or another of three companies that worked with BP on the well: Transocean LTD, which owned the Deepwater Horizon oil rig and the blowout preventer; Halliburton Inc., which was responsible for encasing the well in cement; and Cameron International Corp, which manufactured the blowout preventer.
President Barack Obama has blasted executives from the companies for pointing the finger of blame at each other during Congressional hearings this month.
In BP's release, Chief Executive Tony Hayward stopped short of assigning responsibility, calling the disaster "a complex accident, caused by an unprecedented combination of failures.
"A number of companies are involved, including BP, and it is simply too early and not up to us to say who is at fault," Hayward said.
BP said its investigation team has begun sharing its findings with the U.S. Department of the Interior.
BP said there was still extensive work to do, including examining major pieces of equipment like the blowout preventer and the rig that are still on the seafloor.
The internal investigation started the day after the rig exploded and caught fire and is being conducted by BP's Head of Group Safety and Operations, who has an independent reporting line to Hayward, the company said.