NY Times
Halliburton officials knew weeks before the fatal explosion of the BP well in the Gulf of Mexico that the cement mixture they planned to use to seal the bottom of the well was unstable but still went ahead with the job, the presidential commission investigating the accident said on Thursday.
In the first official finding of responsibility for the blowout, which killed 11 workers and led to the biggest offshore oil spill in American history, the commission staff determined that Halliburton had conducted three laboratory tests that indicated that the cement mixture did not meet industry standards.
The result of at least one of those tests was given on March 8 to BP, which failed to act upon it, the panel’s lead investigator, Fred H. Bartlit Jr., said in a letter delivered to the commissioners on Thursday. “There is no indication that Halliburton highlighted to BP the significance of the foam stability data or that BP personnel raised any questions about it,” Mr. Bartlit said in his report.
Another Halliburton cement test, carried out about a week before the blowout of the well on April 20, also found the mixture to be unstable, meaning it was unlikely to set properly in the well, but those findings were never sent to BP, Mr. Bartlit found after reviewing previously undisclosed documents.
Although Mr. Bartlit did not specifically identify the cement failure as the sole or even primary cause of the blowout, he made clear in his letter that if the cement had done its job and kept the highly pressurized oil and gas out of the well bore, there would have been no accident.
“We have known for some time that the cement used to secure the production casing and isolate the hydrocarbon zone at the bottom of the Macondo well must have failed in some manner,” he said in his letter to the seven members of the presidential commission. “The cement should have prevented hydrocarbons from entering the well.”
The failure of the cement set off a complex and ultimately deadly cascade of events as oil and gas exploded upward from the 18,000-foot-deep well. The blowout preventer, which sits on the ocean floor atop a well and is supposed to contain a well bore breach, also failed.
In an internal investigation, BP identified the faulty cement job as one of the main factors contributing to the accident and blamed Halliburton, the cementing contractor on the Macondo well, as the responsible party. Halliburton has said repeatedly in public testimony that it tested and used a proper cement formula and that BP’s flawed well design and poor operations caused the disaster.
Jesse Gagliano, a Halliburton technical adviser, told federal investigators in Houston in August that the company was confident of the cement job and said that BP’s decision to use six well-stabilizing devices known as centralizers contributed to the failure of the cement work.
Another Halliburton official, Thomas Roth, told a National Academy of Engineering panel last month that Halliburton’s cement met industry standards and that it had been successfully used at more than 1,000 other wells. Mr. Roth said BP ignored “multiple red flags” in the drilling and completion of the well.
The Deepwater Horizon drilling rig was operated by a third company, Transocean.
Cathy Mann, a Halliburton spokeswoman, said the company was reviewing the panel’s findings. A BP spokesman said the company would have no comment.
Halliburton, a major oil field services company and one of the nation’s largest defense contractors, was once led by former Vice President Dick Cheney. Mr. Bartlit’s law firm, Bartlit Beck Herman Palenchar & Scott, has done legal work for Halliburton in the past but has not represented the company since 2005, the firm said.
The commission obtained from Halliburton samples of the same cement recipe used on the failed well, including the same proportion of nitrogen used as a leavening agent and a number of chemicals used to stabilize the mixture. The slurry was sent to a laboratory owned by Chevron for independent testing.
Chevron conducted nine separate stability tests intended to reproduce conditions at the BP well and the cement failed them all, the staff report said.
“Although laboratory foam stability tests cannot replicate field conditions perfectly,” Mr. Bartlit’s letter said, “these data strongly suggest that the foam cement used at Macondo was unstable.”
One and a half gallons of the actual mixture used on the doomed BP well survived and are being held as evidence in criminal and civil investigations.
Shortly before technicians began pumping cement slurry down the well on April 19, Halliburton conducted one last test of the mixture. The Texas concrete contractors changed some of the conditions of the test and appeared satisfied with the result, although those findings were not communicated to BP until after the well explosion, the commission found.
The commission concluded, “Halliburton may not have had — and BP did not have — the results of that test before the evening of April 19, meaning that the cement job may have been pumped without any lab results indicating that the foam cement slurry would be stable.”
Further, the panel found, “Halliburton and BP both had results in March showing that a very similar foam slurry design to the one actually pumped at the Macondo well would be unstable, but neither acted upon that data.”
The commission, appointed by President Obama in May, is led by Bob Graham, the former senator and governor of Florida, and William K. Reilly, a former administrator of the Environmental Protection Agency. The commission is scheduled to present its interim findings on Nov. 8-9 and its final report to the president in mid-January. It released this report early, it said, because other wells may be planning to use similarly flawed cement.
Mr. Bartlit, who conducted a much-praised investigation of the 1988 Piper Alpha blowout in the North Sea off Britain that killed 167 workers, said the flawed cement was not the whole story. Many human and mechanical failures combined to create the disaster, he said, and backup procedures were skipped or ignored.
“Because it may be anticipated that a particular cement job may be faulty, the oil industry has developed tests, such as the negative pressure test and cement evaluation logs, to identify cementing failures,” he wrote. “It has also developed methods to remedy deficient cement jobs. BP and/or Transocean personnel misinterpreted or chose not to conduct such tests at the Macondo well.”
In its investigation, BP said that on the morning of April 20, its concrete construction team decided not to conduct a cement evaluation log. It said that in relying on other types of assessments, the team ignored BP’s own guidelines.
