The Macondo well had been problematic from the start as the crew drilled into brittle rock that caused losses of thousands of barrels of the drilling fluid, or “mud,” that is crucial to any such operation.
“With the known losses experienced in the well, BP’s failure to take additional precautions, such as establishing additional barriers during cementing, was a contributing cause of the blowout,” the report said.
The rig crew should have detected the unfolding disaster and taken different steps once the mud began shooting out of the well onto the rig, followed by gas, the report said. The entire operation should have been shut down long before the gas emerged and exploded, it concluded.
“The failure of the rig crew to stop work on the Deepwater Horizon after encountering multiple hazards and warnings was a contributing cause of the Macondo blowout,” the report said.
When things began to go catastrophically wrong that evening on the rig, the crew either waited too long to respond or took the wrong steps to cope with the surge of gas from the high-pressure hydrocarbon reservoir, the report said. For example, the report said, the decision to disconnect from the well and seal the pipe came too late, after an explosion had already disabled the cables and lines leading to the blowout preventer on the sea floor.
Transocean spokesman Brian Kennedy responded Wednesday, “We take strong exception to criticism of the Horizon drill crew, nine of whom perished fighting to save their fellow crew members and the rig, for the actions they took in the face of such an unprecedented emergency.”
Although the bureau did not call into question the safety of deep-water drilling in general, it recommended a number of changes in drilling practices and suggested that water depth matters when it comes to detecting and responding to a gas “kick,” which can lead to a blowout.