BP has blamed its own engineers for a fatal drilling disaster that triggered the largest US oil spill and said rig owner Transocean and contractor Halliburton also must shoulder some of the blame.
BP's internal investigation of the Deepwater Horizon rig disaster in April cited at least eight errors of judgment and equipment failures that allowed natural gas to erupt from the subsea Macondo well 64km off the Louisiana coast, killing 11 workers and eventually sinking the $365 million vessel.
In the report, released today on BP's website, the London-based oil and gas producer pinned some of the blame on its employees for the catastrophe, which spewed more crude into the Gulf of Mexico over 87 days than two supertankers could hold.
The report, compiled by a team of investigators who reported to BP's chief of safety Mark Bly said representatives of Transocean and Halliburton also bore some responsibility for the explosion and spill that shut a wide swath of fishing grounds for months and brought US deepwater oil exploration to a standstill.
Transocean employees drilled the $140 million well under BP supervision. Halliburton was paid to line the hole with cement. BP, the largest oil and gas producer in the US section of the Gulf, was hours from finishing the Macondo well about one mile under the sea surface when it erupted.
Mistakes began with flawed cementing of the wellbore and continued as BP and Transocean crew members misinterpreted a pressure test. Further mistakes included the crew's failure to direct the blowout over the side of the rig, which may have prevented the explosion, the report's executive summary said.
Transocean and Halliburton were not immediately available for comment.
BP was paying Transocean about $500,000 a day to lease the Deepwater Horizon.
The company is facing hundreds of lawsuits from oystermen, shrimpers, fishermen, beachside hotel owners and others who claim the spill caused financial losses.
One finding of the so-called Bly report was that BP managers aboard the rig misinterpreted a test of the well's stability on April 20th and began replacing drilling fluid, which is heavier than oil and natural gas, with seawater.
The seawater was too light to prevent natural gas that had begun leaking into the well from shooting up the pipe to the rig, where it exploded.
A federal investigative panel comprised of US coast guard officers and Interior Department regulators has focused on how BP employees aboard the rig and in Houston failed to detect signals that the well was about to erupt. The panel is scheduled to conduct another week of hearings beginning October 4th in New Orleans.
The US justice department and several Congressional committees also are conducting inquiries.
Under an agreement brokered with the Obama administration, BP agreed to set aside $20 billion to cover claims and damages.
Bloomberg