Halliburton May Have Pumped Unstable Cement Down BP Oil Well
WASHINGTON, DC, October 29, 2010 (ENS) – The cement mixture used by Halliburton to close off BP’s Deepwater Horizon oil well was too “unstable” to stop the blowout and Halliburton knew it from tests conducted before the April 20 explosion, according to a report to the national commission investigating causes of the disastrous oil spill.
On April 20, BP had finished its test well, known as the Macondo well, 18,000 feet below the surface of the Gulf of Mexico and about 40 miles southeast of the Louisiana coast. Halliburton was contracted to seal the well with cement to prevent the escape of oil and gas until BP was ready to proceed with drilling and extraction.
To seal the well, “Halliburton generated the nitrogen foam cement by injecting high pressure nitrogen into a base cement slurry as it pumped that slurry into the well,” wrote Fred H. Bartlit Jr., chief counsel to the National Commisson on the BP Deepwater Horizon Oil Spill and Offshore Drilling, in letter to the commission dated October 28.
“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,” wrote Bartlit.
“That cement should have prevented hydrocarbons from entering the well,” wrote Bartlit.
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The Deepwater Horizon oil rig leased by BP on fire in the Gulf of Mexico, April 22, 2010 (Photo courtesy U.S. Coast Guard) |
But instead, about 10:30 on the night of April 20, the Macondo well exploded, killing 11 Deepwater Horizon crewmembers, injuring 17 others and unleashing the largest oil spill in history. About 4.1 million barrels entered gulf waters, while another 800,000 barrels was retrieved for refining. Over 1,000 miles of shoreline were impacted along with wildlife, from whales, turtles and birds to microscopic organisms.
To investigate issues surrounding cement failure, Bartlit and his legal team asked Halliburton to supply them with samples of materials “like those actually used at the Macondo well.”
On April 19 and 20, Halliburton generated the nitrogen foam cement by injecting high pressure nitrogen into a base cement slurry as it pumped that slurry into the well.
Bartlit received from Halliburton “off-the-shelf cement and additive materials used at the Macondo well from their stock.” He told the Commission that he was satisfied that although these materials did not come from the specific batches used at the Deepwater Horizon well, “they are in all other ways identical in composition to the slurry used there.”
Chevron agreed “as a public service” to test the cement slurry on behalf of the Commission, Bartlit wrote, saying that Chevron employs some of the industry’s most respected cement experts, and maintains a state-of-the art cement testing facility in Houston, Texas.
Halliburton agreed that the Chevron lab was highly qualified for this work, Bartlit stated.
Chevron reported that its lab personnel were unable to generate stable foam cement in the laboratory using the materials provided by Halliburton and available design information regarding the slurry used at the Macondo well.
“Although laboratory foam stability tests cannot replicate field conditions perfectly, these data strongly suggest that the foam cement used at Macondo was unstable,” Bartlit wrote. “This may have contributed to the blowout.”
Halliburton has stated publicly that it tested the Macondo cement before pumping it on April 19 and 20, and that its tests indicated the cement would be stable, Bartlit pointed out.
When the preliminary test results from the Chevron lab showed the cement slurry was not stable, Barlit and his legal team requested the results of Halliburton’s own tests.
Documents provided by Halliburton showed that four tests of the cement slurry were conducted – two in February and two in April. Only the last one, conducted sometime after April 13, produced a stable mixture.
Bartlit details these four tests in his letter to the Commission. After reviewing the test results and emails between the two companies, the legal team concludes:
- Only one of the four tests discussed above that Halliburton ran on the various slurry designs for the final cement job at the Macondo well indicated that the slurry design would be stable
- 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
- 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
- Halliburton (and perhaps BP) should have considered redesigning the foam slurry before pumping it at the Macondo well
In a statement responding to Bartlit’s letter, Halliburton Thursday defended its actions, saying, “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 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.”
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Oil covers the surface of the Gulf of Mexico (Photo by Katie Davison courtesy Greenpeace) |
Halliburton also noted that “it has been unable to provide the Commission with cement, additives and water from the rig because it is subject to a Federal Court preservation order but that these materials will soon be released to the Marine Board of Investigation.
Now, a New Orleans federal judge overseeing Deepwater Horizon litigation has ordered Halliburton to turn over cement to federal investigators.
“No destructive testing on the cementing components will be conducted without further order of the court,” Judge Carl Barbier wrote in his October 27 order, issued today.
Bartlit takes care to point out to the Commission that “even if our concerns regarding the foam slurry design at Macondo are well founded, the story of the blowout does not turn solely on the quality of the Macondo cement job. Cementing wells is a complex endeavor and industry experts inform us that cementing failures are not uncommon even in the best of circumstances.”
“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. It has also developed methods to remedy deficient cement jobs,” Bartlit explained. “BP and/or Transocean personnel misinterpreted or chose not to conduct such tests at the Macondo well.”
President Barack Obama established the Commission on May 22, 2010 to examine the facts and circumstances to determine the cause of the Deepwater Horizon oil disaster, develop options for guarding against future oil spills from offshore drilling, and submit a final public report to the President with its findings within six months of the Commission’s first meeting, which opened July 12, 2010.
The Commission is co-chaired by Bob Graham, a former two-term governor of Florida who served for 18 years in the U.S. Senate, and William Reilly, administrator of the U.S. Environmental Protection Agency (1989-1993) and presently founding partner of Aqua International Partners, LP, a private equity fund investing in water and renewable energy companies.
Commission members are:
- Frances Beinecke, president of the Natural Resources Defense Council
- Donald Boesch, president of the University of Maryland Center for Environmental Science, professor of marine science
- Terry Garcia, executive vice president for Mission Programs for the National Geographic Society
- Cherry Murray, dean of the Harvard School of Engineering and Applied Sciences
- Frances Ulmer, chancellor of the University of Alaska Anchorage and member on the Special Committee on the Exxon Valdez Oil Spill Claims Settlement
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