A series of flawed decisions by companies working on BP’s failed Macondo well, poor oversight by federal regulators and a “misplaced trust” in emergency equipment guarding the site led to the lethal Deepwater Horizon disaster, the National Academy of Engineering concluded today.
The 136-page report by the NAE and the National Research Council broadly echoes the findings of other investigations into the 2010 oil spill by insisting that companies did not heed numerous warning signs as they worked on the Macondo well in the Gulf of Mexico last year.
“The lack of a strong safety culture … is evident in the multiple flawed decisions that led to the blowout,” according to the report by a 15-member panel of geophysics experts, petroleum engineers and scientists. “Industrial management involved with the Macondo well-Deepwater Horizon disaster failed to appreciate or plan for the safety challenges presented by the Macondo well.”
When the Macondo well blew out on April 20, 2010, it triggered a lethal explosion aboard the Deepwater Horizon drilling rig, killing 11 workers, injuring 16 others and unleashing the nation’s worst oil spill.
Donald Winter, the former secretary of the Navy who headed the 15-member NAE committee that investigated the oil spill, said major changes are needed to prevent a repeat of the disaster. Chief among them, he said, is paying greater attention — and adopting a broad, holistic approach — to managing risks and emphasizing safety in all stages of offshore drilling.
“Industry and regulators need to include a factual assessment of all the risks in deep-water drilling operations in their decisions and make the overall safety of the many complex systems involved a top priority,” Winter said.
Echoing the presidential commission that investigated the Deepwater Horizon disaster, the NAE panel insisted that the U.S. should remake its approach to regulating offshore drilling by following the lead of Norway, the United Kingdom and other countries that pair some proscriptive regulations with a performance-based approach that hinges on systematic risk management practices.
“The United States should fully implement a hybrid regulatory system that incorporates a limited number of prescriptive elements into a pro-active, goal-oriented risk management system for health, safety, and the environment,” the NAE committee said.
The panel noted that many of its recommendations dovetail with steps that have already been taken to boost oversight of the industry. But the group said Congress and the administration still need to provide “the funding and flexibility in hiring practices” that will allow offshore drilling regulators to go head-to-head with industry.
Interior Secretary Ken Salazar stressed that the government has already made many of the changes NAE recommended.
“The work we have done to implement rigorous new offshore drilling and safety rules and reform offshore regulation and oversight is in line with the recommendations of the committee and with our goals moving forward,” Salazar said in a statement.
Winter said the regulatory change was a step in the right direction but said it was unclear whether “it represents a transient response” to the Deepwater Horizon disaster. Even so, Winter insisted that it makes sense to continue offshore drilling now, though “further improvements” are needed.
“Given all the improvements that have already been made” including new regulations and technologies for containing runaway subsea wells, “we think that it is in fact a reasonable process to continue drilling at this time,” Winter said.
The NAE report called for major changes to the way emergency equipment known as blowout preventers are designed and used to help control surges of oil and gas at wells. Powerful pipe-cutting and closing rams on the BOP used at the Macondo well failed to successfully shear through drill pipe and seal off the well bore.
“BOP systems should be redesigned to provide robust and reliable cutting, sealing, and separation capabilities for the drilling environment to which they are being applied and under all foreseeable operating conditions of the rig on which they are installed,” the NAE concluded. At the same time, workers need to be better trained to operate the devices in emergencies.
Winter stressed that the BOP used at the Macondo well “was neither designed nor tested for the dynamic conditions that most likely existed (during) attempts to recapture well control.” And, he said, that was the case despite “numerous warnings about the potential failure of BOPs even before the Macondo well blowout.”
Overall, Winter said, the offshore drilling industry — and the crew working on the Macondo well — pinned too much trust on the blowout preventer.
“There was a level of confidence on the part of the crew that if anything didn’t work out right, they could count on the blowout preventer,” Winter said. There was, at the time, a “misplaced confidence that the blowout preventer could provide a guarantee, if you will, an insurance policy against a blowout.”
But Winter noted that blowout preventers — like parachutes on a plane — are only meant to be used as a final, last-ditch backup. In offshore drilling, “the primary means of well control is associated with design of the well itself,” Winter stressed.
The National Academy of Engineering pinned much of the blame for the disaster on the decision to proceed with temporarily abandoning the well — so it could be hooked up to a production facility later — even though workers at the site had not confirmed that cement barriers at the site were sound. Investigators separately concluded that negative pressure tests conducted on the cement applied at the site were misinterpreted.
“We viewed the decision to proceed with temporary abandonment … as being the pivotal decision that led to the eventual blowout of the well,” Winter told reporters today. “Up until that point in time, the team did have control of the well. Once they made the decision to basically disregard the results of the tests that were conducted … and to proceed to temporary abandonment, they set the course for the subsequent events.”
In preparing to temporarily abandon the well, BP chose to displace heavy drilling muds with lighter seawater — a move the NAE said was a “questionable decision” that may have left the well perilously vulnerable.
Throughout the Macondo project, companies working at the site, including well operator BP, drilling rig owner Transocean Ltd., and the cement contractor Halliburton Co., were outmatched by the risks of drilling and managing the well, the NAE said.
“The team was attempting to drill with a challenging well geology,” Winter said. “The approach they chose to seal the well failed to provide an adequate barrier.”
At the site, companies were forced to work within a slim drilling margin — the difference between the pore pressure exerted by oil and gas in the underground formation and the countervailing weight and pressure of drilling fluids at the site. If the downhole drilling mud pressure exceeds the forces exerted by the formation itself, it can cause cracks to develop.
The narrow drilling margin raised the risks associated with the Macondo project and put a premium on making sure the well was adequately secured.
In the weeks before the April 20, 2010 blowout, the Deepwater Horizon drilling team encountered unexpected kicks of hydrocarbon at the site and cases where drilling fluids were lost in the well — an indication that the formation had cracked.
BP said in a statement that the NAE’s conclusions “are consistent with the consensus which has emerged from every official investigation: that the Deepwater Horizon accident was complex and was the result of multiple causes, involving multiple parties.”
The National Academy of Engineering acknowledged some things may never truly be known, including the precise path of hydrocarbons to the surface, “since the requisite forensic evidence lies more than two miles beneath the seabed.” The 11 workers who perished in the disaster also may have shed light on pivotal decisions made onboard the rig.
Winter admitted that the information the panel could get “was constrained by the legal environment” surrounding the civil litigation tied to the oil spill and the multiple investigations into the incident, including the Justice Department’s criminal probe. But Winter said companies were generally cooperative and still provided some info to the panel. Houston-based Cameron, which made the blowout preventer used at the site, “provided some material but declined to make a presentation on the Deepwater Horizon BOP,” Winter said.
Winter complained that the NAE did not receive the results of additional testing of the blowout preventer, which was led by BP and conducted after a federal examination of the device was completed.
Check out this summary of the NAE’s conclusions and recommendations or view the report below.