Risk register · entry
Q3 · EngineeredDeepwater Horizon
The failsafe was a blowout preventer. It buckled the very pipe it was built to shear.
Tightly coupled systems where one small fault cascades and takes down the whole machine.
Why this quadrant
The blowout preventer was defeated by the event it was installed to stop. The CSB found that emergency well-control put the drill pipe into effective compression, buckling it inside the device and pushing it off the cutting surface of the blind shear ram, which then punctured the pipe rather than shearing it and increased the flow. Nothing was dormant or defective beforehand, and nothing on the rig would have shown the crew what was happening.
The record
- BP's cumulative pre-tax income statement charge for the incident reached $61,597 million (approximately $61.6 billion) as disclosed in its second-quarter 2016 results filed with the SEC.certain
- The 20 April 2010 blowout and explosion killed 11 personnel aboard the rig and seriously injured 17 others.certain
- The well flowed uncontrolled for 87 days, from 20 April to 15 July 2010.certain
- EPA states that approximately four million barrels of oil flowed from the damaged Macondo well over the 87-day period.high
- BP's October 2015 settlement with the United States included a $5.5 billion Clean Water Act civil penalty, the largest in the history of the Act, within a $14.9 billion federal settlement.certain
Sources
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