A report found a string of failures by "multiple companies" led to the deadly Deepwater Horizon disaster, and BP is taking the blame for the blowout that spewed millions of gallons of oil into the Gulf of Mexico.
A four-month investigation, conducted by a team of specialists from inside and outside BP, found:
- The cement and shoe track barriers -- and in particular the cement slurry that was used -- at the bottom of the Macondo well failed to contain hydrocarbons within the reservoir, as they were designed to do, and allowed gas and liquids to flow up the production casing.
- The results of the negative pressure test were incorrectly accepted by BP and Transocean, operator of the drilling platform, although well integrity had not been established.
- Over a 40-minute period, the Transocean rig crew failed to recognise and act on the influx of hydrocarbons into the well until the hydrocarbons were in the riser and rapidly flowing to the surface.
- After the well-flow reached the rig it was routed to a mud-gas separator, causing gas to be vented directly on to the rig rather than being diverted overboard.
- The flow of gas into the engine rooms through the ventilation system created a potential for ignition which the rigs fire and gas system did not prevent.
- Even after explosion and fire had disabled its crew-operated controls, the rigs blow-out preventer on the sea-bed should have activated automatically to seal the well. But it failed to operate, probably because critical components were not working.
"It is evident that a series of complex events, rather than a single mistake or failure, led to the tragedy. Multiple parties, including BP, Halliburton and Transocean, were involved," said Tony Hayward, BP's outgoing chief executive.
To put it simply, there was a bad cement job and a failure of the shoe track barrier at the bottom of the well, which let hydrocarbons from the reservoir into the production casing. The negative pressure test was accepted when it should not have been, there were failures in well control procedures and in the blow-out preventer; and the rigs fire and gas system did not prevent ignition," he said.
Based on the report, it would appear unlikely that the well design contributed to the incident, as the investigation found that the hydrocarbons flowed up the production casing through the bottom of the well, added Hayward, whom BP recently reassigned to Russia.
The April 20 fire, explosion and sinking of the Deepwater Horizon drilling platform killed 11 workers, and the subsequent oil spill killed unknown numbers of birds, fish and other sea creatures.
Gulf communities from Louisiana to Florida are still cleaning up oil that washed ashore, and scientists say at least one large underwater plume of oil could create further environmental havoc.
BP has established a $20 billion compensation fund to pay claims, and this week gave $10 million to the National Institutes of Health to study the potential health effects of the spill.
"We are determined to learn the lessons for the future and we will be undertaking a broad-scale review to further improve the safety of our operations. We will invest whatever it takes to achieve that. It will be incumbent on everyone at BP to embrace and implement the changes necessary to ensure that a tragedy like this can never happen again," Hayward said.
Chairman of the Board Carl-Henric Svanberg said, I believe this report will be of significant value in helping the overall understanding of how this tragedy occurred. It is of the utmost importance to the board to ensure that BP learns from this and further enhances the safety of its operations for the future.
Based on its key findings, the investigation team has proposed a total of 25 recommendations designed to prevent a recurrence of such an accident. The recommendations are directed at strengthening assurance on blow-out preventers, well control, pressure-testing for well integrity, emergency systems, cement testing, rig audit and verification and personnel competence.
While agreeing that there were many "combined failures," Jim Zabcik, a petroleum engineer for Merlon International, said BP was attempting "to share the blame."
"BP was the operator, Transocean was the sub-contractor.On the rig floor, the operator has final say, not the sub-contractor," Zabcik said from his Houston office.
"There exists a real time ebb and flow of ideas in this relationship, but at the end of the day the operator has the only vote. It would appear to me that BP is trying to 'draw in' Transocean into the line of fire. Lets not forget that Halliburton recommended more centralizers than BP ran.But Halliburton can only recommend and had no authority on the rig floor."
Zabcik believes that human fatigue entered into the calamitous equation.
"(The workers) had been on this well a long time and were weary. Weary of the many delays to that point. The end of the operation was near and impatience was the dominant emotion on the rig floor.This is what can happen when emotions trump thinking," Zabcik said.
BP said additional relevant information may be forthcoming --for example, when Halliburtons samples of the cement used in the well are released for testing and when the rigs blow-out preventer is fully examined now that it has been recovered from the sea-bed. There will also be additional information from the multiple ongoing federal investigations.
After the disastrous spill, the Obama administration imposed a moratorium on deep-water drilling -- a move that the oil industry and the state of Louisiana are contesting.
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Contact Kenric Ward at kward@sunshinestatenews.com or at (772) 801-5341.
