In the Deepwater Horizon oil rig’s final hours, BP officials say a critical decision was made to continue work on the undersea well, even after a test warned that something was wrong. According to The Wall Street Journal, in a congressional memo released yesterday, BP officials said the decision to continue work may have been “a fundamental mistake”.
The memo, which outlines a briefing for congressional staff by BP officials that occurred early Tuesday, was written by Reps. Henry Waxman (D., Calif.) and Bart Stupak (D., Mich.). Their committee, the House Energy and Commerce Committee, has been investigating the conduct of BP and other companies with personnel aboard Deepwater Horizon the day of the explosion.
The test the memo refers to is called a negative pressure test, and checks for leaks in a well. The negative pressure test detailed in the memo was performed just hours before the April 20 explosion. According to the Journal, BP earlier had said the test was inconclusive at best and “not satisfactory” at worst.
But at Tuesday’s meeting, BP officials called the results of the negative pressure test an “indicator of a very large abnormality.” At 7:55 p.m., however, unnamed workers aboard Deepwater Horizon determined that the test was successful after all. After that, workers began to remove the heavy drilling fluid, called “mud”, that provides pressure to prevent any gas that seeps into the well from rising to the surface.
According to a report in The Washington Post, BP also cited problems with the cementing job done by Halliburton Energy Services, Inc. Apparently, one procedure had to be attempted nine times, which might have indicated “contamination of the cement.” The cement is meant to seal off the well from volatile natural gas.
The memo also said that BP’s investigation had “raised concerns about the maintenance history, modification, inspection, and testing of” the blowout preventer. The blowout preventer is meant to stop the uncontrolled flows of oil and natural gas like the one that brought down the Deepwater Horizon. In the case of Deepwater Horizon, the blowout preventer for some reason failed to shear off the pipe and seal the gushing well.
Finally, according to the memo, BP’s investigation raised other questions whether proper procedures were followed for critical activities on the day of the explosion. According to the Post, most of these involved management of drilling mud.
According to The Wall Street Journal, the memo does not identify who on the rig made key decisions in the hours before the explosion. At the time, personnel from TransOcean, LTD., the owner of the rig, BP and Halliburton were all aboard. Most of the work aboard the rig was performed by employees of TransOcean and other contractors, the Journal said.
A TransOcean spokesperson told the Journal that the well was constructed and completed at the direction of BP. A Halliburton representative responded by saying its contractors followed BP’s instructions in regards to the cement work.
A BP spokesperson declined to comment on the memo’s specific statements, the Journal said.