Blowout preventer deepwater horizon

Soon after the occurrence of the Deepwater Horizon tragedy. President Obama set up a commission to look into its causes and to make recommendations as to how such events could be avoided in the future. The committee issued its report in January 2011 (National Commission 2011), although critical information—particularly the conditions of the Blowout Preventer—was not known at the time of publication. 

Conditions at the deep ocean seabed are always just a few degrees above freezing. The oil reservoir itself - probably more than a billion barrels - was a further 4.5 km below the seabed, where the temperature would be about 100°C. Figure 14.3 gives a schematic representation of the layout, comprising Deepwater Horizon on the surface, the blowout preventer (BOP) on the seabed nearly 5000 feet - some 1500 m -below the surface, and the hydrocarbon reservoir 18,360 feet (nearly 6000 m) below the surface. 

The Macondo-Deepwater Horizon accident is the most complex of accidents. It was a combination of Complicated and highly specialized technical issues about how to seal a difficult well far below the seabed in deepwater the design, manufacturing and testing of a blowout preventer that was supposed to operate extremely reliably almost 5000 feet (1500 m) below sea level poor decision making and unclear contractual divisions of responsibilities between the main parties. 

In short, well integrity was not established, because the cement plug had failed. Oil and gas entered the well and well control was lost. A large kick of gas overwhelmed the mud/gas separator on Deepwater Horizon and then ignited, and the high-integrity blowout preventer (BOP) 5000 feet below on the seabed failed to operate as intended. 

As previously stated, the blowout preventer (BOP) was designed and manufactured by Cameron International of Houston, Texas. It was owned and maintained by Trans-ocean, the owners of Deepwater Horizon. Failure of the BOP was an absolutely key aspect of the accident this was a multiple-channel high-integrity redundant systan, the sole function of which was, in extremis, to cut the drill pipe within the well bore and seal off the well, and yet it did not work. 

Forensic examination of Deepwater Horizon blowout preventer. Final report for United States Department of the Interior, vols. 1 and 2 and Addendum, DetNorske Veritas (DNV), Report No. EP030842, March 20, 2011. 

---