LONDON/WASHINGTON--BP Plc and its Gulf of Mexico oil well partners traded blame on Wednesday after an internal BP investigation tried to downplay the company's role in the world's biggest offshore spill.
The 193-page BP report offered a preview of how the British oil giant plans to vigorously defend itself against lawsuits arising from the disaster and any charges of gross negligence, which carry fines potentially in excess of $20 billion.
BP accepted some responsibility for the disaster but pointed the finger at what it said were major failures by Transocean Ltd, the operator of the ill-fated Deepwater Horizon oil rig, and oil services company Halliburton, which cemented the deep-sea well that ruptured on April 20.
The report drew fire from a prominent U.S. lawmaker who accused BP of trying to minimize its role in the disaster. Transocean called it a "self-serving" attempt by BP to escape responsibility for its "fatally flawed" well design, while Halliburton said the report was filled with inaccuracies.
The report threatened to reignite public anger over the massive spill, which caused an environmental catastrophe along the U.S. Gulf Coast, devastated tourism and fishing in the area and damaged President Barack Obama's popularity. Obama's spokesman, Robert Gibbs, declined to comment on BP's findings and said the government was still investigating the disaster to "find out what went wrong and hold those responsible accountable for the damage that's been done."
BP investigators were unable to identify any single action or inaction that caused the Deepwater Horizon rig to blow up on April 20, killing 11 workers, after the Macondo well ruptured.
"Rather, a complex and interlinked series of mechanical failures, human judgments, engineering design, operational implementation and team interfaces came together to allow the initiation and escalation of the accident," the report said. "Multiple companies, work teams and circumstances were involved over time."
Investors had been eagerly awaiting the report to find out whether BP would be able to share the potential costs of the spill--estimated by some analysts to exceed $50 billion. Citigroup analysts said in a research note that BP's report "appears to support the case for no negligence," but they acknowledged that the findings of the internal investigation were unlikely to be accepted as objective.
BP shares trading in New York closed up 3.2 percent, while shares of Transocean were 1.3 percent higher and those of Halliburton were up 1.2 percent. Standard & Poor's downgraded Transocean's rating to BBB from BBB-plus, saying the Swiss-based company faced uncertain liabilities arising from the disaster.
The U.S. Justice Department could pursue a variety of civil and criminal charges against the companies involved in the spill. Any penalties could be in the billions of dollars.
The ruptured well unleashed a torrent of crude that spewed until it was capped three months later on July 15, after 4.9 million barrels of oil had leaked into the sea. The top U.S. official overseeing the spill response, retired Coast Guard Admiral Thad Allen, said on Wednesday that BP may not start the final "kill" of its well until mid- to late September.
The BP report, overseen by BP's head of safety, Mark Bly, highlighted eight key failures that led to the blowout of the well and the subsequent explosion aboard the rig. It defended BP's much-criticized single-casing well design; the use of fewer-than-recommended centralizers (devices used to ensure the cement casing is applied evenly around the well); and the decision to replace heavy drilling mud, which was keeping the well under control, with lighter water.