The owner of the Deepwater Horizon drilling rig that exploded last spring, killing 11 rig workers and sparking the nation's worst oil spill, is placing the blame for the disaster largely on BP PLC.
In a new internal probe released today, Transocean Ltd. says the rig explosion and subsequent oil spill resulted from a series of bad decisions made by BP. The report also blasts BP for failing to communicate potential danger to Transocean.
"The Macondo incident was the result of a succession of interrelated well design, construction, and temporary abandonment decisions that compromised the integrity of the well and compounded the risk of its failure," the report says. "The decisions, many made by the operator, BP, in the two weeks leading up to the incident, were driven by BP's knowledge that the geological window for safe drilling was becoming increasingly narrow."
Transocean said its investigation found the disaster resulted from four overarching issues: risk management and communication, well design and construction, risk assessment, and process safety and operations.
The report says BP failed to properly manage risk or communicate those risks to its contractors. The oil giant also failed to adjust its well design as conditions changed, indicating the potential for problems, the report says. The Transocean team also cites evidence that BP and Halliburton Co. did not properly require or confirm critical cement tests, despite indications the cement would not be stable.
"It does not appear that BP used risk assessment procedures or prepared Management of Change documents for these decisions or otherwise addressed these risks and the potential adverse effects on personnel and process safety," the report says.
A spokesman for BP did not immediately respond to requests for comment.
Transocean's report also addresses the faulty blowout preventer that failed to staunch the flow of oil and gas. The company said the 300-ton device and its control system were fully operational at the time of the incident and functioned as designed. Transocean was responsible for maintaining the blowout preventer throughout the well-drilling process.
"However, it was overcome by the extreme dynamic flow, the force of which pushed the drill pipe upward, washed or eroded the drill pipe and other rubber and metal elements, and forced the drill pipe to bow within the BOP," the report says. "This prevented the BOP from completely shearing the drill pipe and sealing the well."
A federal investigation into the disaster blamed the failure of the blowout preventer on a design flaw and on a bent piece of drill pipe. That investigation also suggested that actions taken by Transocean personnel as they attempted to control the well could have contributed to the lodged drill pipe.
Transocean's report is the latest in a string of finger-pointing about the April 20 disaster. In its own internal probe, BP placed some of the blame on its contractors, Transocean and Halliburton. And Halliburton has pointed its finger back to BP, saying the well operator cut corners and skipped crucial tests that would have indicated problems with Halliburton's cement.
The companies are carefully treading around the blame issue as culpability in the disaster, fines, liability for cleanup costs and future offshore operating status are all yet to be determined.
But some independent investigations into the disaster have found all three companies to be at least partially culpable. A report from the presidential commission investigating the disaster found that the disaster was caused by a "failure of management" by all three companies involved in the project and called for an overhaul of the federal offshore drilling regulatory system. And an investigation released in April from the U.S. Coast Guard harshly critiqued Transocean, saying improper maintenance, insufficient training and poorly designed safety systems contributed to the disaster. Transocean has refuted those findings.
Rep. Ed Markey of Massachusetts, the ranking Democrat on the House Natural Resources Committee and the chief author of an oil-spill response measure that is currently stalled in the House, said, "This is the newest salvo in the continuing circular finger-pointing contest among BP, Transocean, Halliburton and others involved in the Gulf oil spill."
"Today's Transocean report says little to shed new light on the details of the disaster, but the problems identified by the spill commission continue to cry out for congressional action to pass comprehensive safety standards for deepwater offshore drilling," Markey added.
Click here to read the report.