Gulf Oil Spill: Congress Finds BP Negligent in Numerous Critical Areas of Deepwater Horizon Rig Well Control

The House committee on energy and commerce released this week a briefing memo, in support of high-risk well regulation, that finds BP failed in three critical areas of well control.

Among many other failures, BP's most serious failures include failing to run cement bond log tests, which could have uncovered failures or imperfections in bonded cement at the well head.

BP failed to test critical hydraulic lines in the blowout preventer. And before cementing the well, BP failed to circulate drilling mud before cementing, in accordance with industry best practices, and choose to circulate seawater instead.

A portion of the briefing memo follows.

"The Committee has also learned that there were several issues with the Deepwater Horizon's maintenance of its blowout preventer (BOP system). There are no MMS regulations requiring testing of emergency systems, and BP did not conduct these tests. ROVs discovered several leaks in the hydraulic lines that provide pressure for BOP functions, and found unexpected modifications to the original design of the BOP. These problems resulted in wasted time in the critical days following the accident and might have contributed to the initial failure of the blowout preventer.

"The Committee's investigation has also uncovered several questions about decisions BP made in regard to the design and execution of the Macondo (Deepwater Horizon) well plan.

"The Macondo well was designed with a long string production casing which extended from the sea floor down to the reservoir from which oil was to be produced. This well design leaves only two barriers along one flow path, through which hydrocarbons could flow between the reservoir and the blowout preventer: a layer of cement at the bottom of the well, and a mechanical seal at the wellhead itself.

"A different design, a liner-tieback approach, would have made a blowout less likely by requiring four barriers between the reservoir and the BOP: two mechanical seals, and two layers of cement.

"The mechanical seal at the wellhead required a lockdown sleeve to seal the well against pressure from below as well as pressure from above. This lockdown sleeve was never installed on the Macondo (Deepwater Horizon) well, even though drillers on the Deepwater Horizon began procedures that would have put upward pressure on the wellhead seal.

"Because the Macondo (Deepwater Horizon) well was designed with a long string casing, it was critically important that the cement job at the bottom of the well successfully seal off the reservoir. But BP cut several corners on its final cement job: it ran casing with an insufficient number of centralizers, required to ensure an even seal around the entire casing; it failed to circulate drilling mud before cementing, in accordance with industry best practices; and it failed to run a cement bond log test, which could have uncovered failures or imperfections in the bonded cement."

Source: House Committee on Energy and Commerce