A key US report on the massive Gulf of Mexico rig disaster has heavily criticised three companies – BP, rig owner Transocean and contractor Halliburton.
The accident caused the worst offshore oil spill in US history and the deaths of 11 workers.
The report examined a cement seal on the well that was put in place the day before the explosion that triggered the spill. It said in the days leading up to the disaster, BP made a series of decisions that complicated cementing operations, added risk, and may have contributed to the ultimate failure of the cement job.
Other companies also shared some of the blame, according to the report, which noted that rig owner Transocean, as owner of Deepwater Horizon, was responsible for conducting safe operations and for protecting personnel onboard.
The details were contained in the final report from an investigation team of the US Coast Guard and the agency that regulates offshore drilling.
The panel held hearings in the year following Deepwater Horizon, which took place on 20 April last year. The US Coast Guard Bureau of Ocean Energy Management Regulation and Enforcement (BOEMRE) investigation was among the most exhaustive.
Other investigations spread around the blame rather evenly, faulting misreadings of key data, the failure of the blowout preventer to stop the flow of oil to the sea and other shortcomings by executives, engineers and rig crew members. The joint investigation team laid considerable blame on BP's shoulders.
The report said the decisions included using only one cement barrier and BP's choice to set the production casing in a location in the Macondo well that created additional risk of influx of oil or gas. The casing is a steel pipe placed in a well to maintain its integrity.
The panel said BP failed to communicate these decisions and the increasing operational risks to Transocean.
“BP, as the designated operator under BOEMRE regulations, was ultimately responsible for conducting operations at Macondo in a way that ensured the safety and protection of personnel, equipment, natural resources, and the environment,” the panel concluded.
The panel recommended further changes to offshore drilling practices, including requiring at least two barriers to be placed in a well – one mechanical, and one cement.
The Macondo well only had a single barrier, the cement seal at the bottom, so when the blowout happened the only thing to stop it was the blowout preventer. That did not work, the panel said, because the kink in the pipe caused by the force of the blowout kept it out of reach of the safety device's shearing rams. The team also said BOEMRE should standardise testing procedures on oil and gas wells.
The reports paints a dark portrait of the final hours aboard the Deepwater Horizon, where the workers in the most danger – on the drilling floor at the centre of the rig – were unaware of the anomalies being detected by engineers looking at data coming from the well. The federal team also charges that BP made decisions blindly, without assessing risk, and in some cases skipping internal processes the company relied on to evaluate the potential dangers of decisions.
While this report and others blame BP for jeopardising safety to cut costs, the federal panel went further and examined the 2009 performance evaluations of 13 BP employees involved on the Macondo well. All but one of the reviews cited cost savings when evaluating the employee's work.
In addition to the rig worker deaths, the resulting oil spill off Louisiana spewed more than 200 million gallons of crude from the undersea. The disaster caused billions of dollars in damage to hundreds of miles of coastline and wreaked havoc on the Gulf economy.
The report pins the causes for the disaster on many of the same faulty decisions found by previous probes, including those by the president's independent oil spill commission, Congressional committees and the companies themselves. But it is likely to carry more weight in Congress, where Republicans in particular have said they are unwilling to adopt reforms until the federal investigation was complete.
Since the disaster, the Obama administration has reorganised the offshore drilling agency and boosted safety regulations. But Congress has yet to pass a single piece of legislation to address safety gaps highlighted by the disaster.
While the federal investigative team lays blame on decisions made by the companies, it does not address the government's own role in approving some of the questionable decisions. The federal agency that oversees offshore drilling signed off on many of the calls made by the companies, sometimes in minutes, and accepted an outdated and erroneous oil spill plan for the well that discussed protecting species that did not even exist in the Gulf of Mexico.
Commenting on the report, BP said: “BP agrees with the report's core conclusion - consistent with every other official investigation – that the Deepwater Horizon accident was the result of multiple causes, involving multiple parties, including Transocean and Halliburton.
“We continue to encourage other parties to acknowledge their roles in the accident and make changes to help prevent similar accidents in the future.”
BP added that it had acknowledged its role in the accident and had taken “concrete steps” to further enhance safety and risk management throughout its global operations.