Fire boat response crews battle the blazing remnants of off shore oil rig Deepwater Horizon off the coast of New Orleans, Louisiana on April 21, 2010. 11 workers are missing after the oil rig exploded on April 20. UPI/U.S. Coast Guard |
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HOUSTON, Oct. 29 (UPI) -- Halliburton Friday criticized a report concluding the cement mixture used on the BP Gulf of Mexico well that exploded was deficient and shifted blame to BP.
The presidential commission headed by former Sen. Bob Graham appointed to investigate the deadly April 19 disaster and subsequent massive oil spill released a report Thursday saying tests performed on a cement mixture comparable to that used by Halliburton showed the mixture was unstable. The report also accused Halliburton of being aware of the mixture's deficiencies.
The Deepwater Horizon oil rig was owned by Transocean and leased by BP.
In a statement posted on its Web site, Halliburton said internal tests conducted on a cement slurry mixture that didn't meet standards in February were preliminary and the mixture was not the same as that used on the ill-fated well.
"Halliburton believes that significant differences between its internal cement tests and the commission's test results may be due to differences in the cement materials tested," the company said. "The commission tested off-the-shelf cement and additives, whereas Halliburton tested the unique blend of cement and additives that existed on the rig at the time Halliburton's tests were conducted.
"BP subsequently instructed Halliburton to increase the amount of retarder in the slurry formulation from eight gallons per 100 sacks of cement to nine gallons per 100 sacks of cement," Halliburton said. "Tests, including thickening time and compressive strength, were performed on the nine gallon formulation (the cement formulation actually pumped) and were shared with BP before the cementing job had begun. A foam stability test was not conducted on the nine gallon formulation."
Halliburton noted cementing wells "is a complex endeavor" and failures are not uncommon in the industry.
"Halliburton believes that had BP conducted a cement bond log test, or had BP and others properly interpreted a negative-pressure test, these tests would have revealed any problems with Halliburton's cement. … BP, as the well owner and operator, decided not to run a cement bond log test even though the appropriate personnel and equipment were on the rig and available to run that test," Halliburton said.
The statement again blamed BP's well design for the disaster as well as the failure of Transocean's blowout preventer.
