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 room
The Macondo blowout is the canonical engineered failure: a tightly coupled drilling system in which the final barrier was defeated by the physics of the event it was installed to arrest. The CSB found that the pressure differential created during emergency well-control put the drill pipe into "effective compression," buckling it inside the blowout preventer and displacing it outside the cutting surface of the blind shear ram, which then punctured rather than sheared the pipe and increased the flow. The failure mode was not a dormant defect but an interaction between well-control actions, flow conditions and the safety device itself, and it was undetectable to the crew in real time, which is the defining signature of q3 rather than q1.
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
The book
This entry is one of 111 in the register. The full story, and what it cost the people who lived it, is in Risky Business by Claudia Zeisberger, David Munro and Joanna Reijgersberg-Siew.
Join the waiting list