Cement job may have caused spill
Work had finished 20 hours before blast
WASHINGTON – An inadequate underwater cement job during the deepwater drilling process is emerging as a potential cause of the devastating oil spill off the Louisiana coast in the Gulf of Mexico.
Officials haven’t said what they think caused the April 20 explosion that led to the sinking two days later of the Deepwater Horizon drilling rig, owned by Transocean Ltd. But industry speculation points to a process where cement is used to seal cracks in the ocean floor surrounding the tubing through which crude oil flows.
Transocean operated the drilling rig under contract for British oil giant BP. Transocean has said the global construction titan Halliburton had just completed “cementing” the 18,000-foot-long well around the time of the explosion.
In a statement Friday, Halliburton confirmed that it was the “cementer” hired for the job and said it had completed its job about 20 hours prior to the explosion.
“The cement slurry design was consistent with that utilized in other similar applications,” the company said. It said all procedures had been “in accordance with accepted industry practice approved by our customers.”
“It is premature and irresponsible to speculate on any specific causal issues,” the statement said.
“We cannot get ahead of ourselves with respect to the facts of this incident,” Guy Cantwell, a spokesman for Transocean in Houston, told McClatchy Newspapers.
Another potential cause for a blowout would be the failure of a hydraulic safety valve system designed to control pressure increases. The valve was made by Cameron International Corp.