By Steven Mufson
Washington Post Staff Writer
Wednesday, May 26, 2010; A07
BP's internal investigation of the Gulf Coast oil spill points to a series of equipment failures, mistakes and missed warning signs that led to the blowout and fire on the Deepwater Horizon drilling rig, according to lawmakers briefed by the company.
BP's investigation, while incomplete, highlights a series of abnormal indicators -- about pipeline pressure and the flow of drilling fluids in the five hours before the explosion -- that should have been "warning signs" of trouble, according to a memo summarizing BP's report. In one case, BP's investigator told lawmakers that a "fundamental mistake may have been made despite" an indicator of a very large abnormality.
BP also said it had concerns about the cementing job in the well, saying that one procedure had to be attempted nine times, which might have indicated "contamination of the cement."
In addition, lawmakers said, "the BP investigation has also raised concerns about the maintenance history, modification, inspection, and testing of" the blowout preventer. The account of BP's investigation was contained in a House Energy and Commerce Committee memorandum.
"In addition, key questions exist about whether proper procedures were followed for critical activities throughout the day," the memorandum said. These mostly had to do with the management of drilling mud, which is used as a counterweight to oil and gas pressure pushing up from below.
Once the blowout began, all the systems in place to prevent disaster broke down in serial fashion, the memorandum said, "including the failure of its emergency disconnect system (EDS), the failure of its automated mode function or deadman switch, the failure of the [blowout preventer's] shearing functions, and the failure of the remote operated vehicle interventions."