Before BP Spill, Halliburton Tests Showed Unstable Cement

WASHINGTON (Dow Jones Newswires), Oct. 28, 2010

Halliburton testing conducted before the BP Gulf of Mexico oil spill showed that cement similar to that pumped into the blown-out well would be unstable, but there is no evidence that the contractor sounded alarms to BP, according to documents obtained by the presidential commission investigating the disaster.

The test data, shared with staff of President Barack Obama's commission on the Deepwater Horizon oil spill, run counter to Halliburton's claims that the nitrogen-cement mixture used in the Macondo well was stable. The data bolster BP's claims that faulty cement contributed to the worst offshore oil spill in U.S. history, but the information doesn't shed light on BP's awareness of the problem.

"Halliburton (and perhaps BP) should have considered redesigning the foam slurry before pumping it at the Macondo well," the spill commission's chief counsel, Fred Bartlit, and other staffers said in a letter sent Thursday to the commission.

Halliburton did share with BP data about one of the faulty tests in March, but there was no evidence that Halliburton highlighted the issue as a red flag or that BP personnel asked questions, the investigators 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 letter said.

Halliburton spokeswoman Cathy Mann said the company was reviewing the report and would respond later. BP didn't immediately respond to a request for comment.

The Deepwater Horizon exploded on April 20, killing 11 workers and marking the beginning of a months-long effort to cap and seal the well. Since then, numerous investigators have been probing the causes of the explosion. Until now, the role of the cement has been murky, in part because Halliburton declined to share with BP the exact formula used in the cement slurry.

The new information reflects the results of four Halliburton foam-stability tests, two conducted in February 2010 and two conducted in April 2010. The first two tests -- using a slightly different cement slurry design from that used in the Macondo well -- indicated that the foam-slurry design was unstable, the letter said.

Of the second two tests -- this time using the actual recipe and design of the cement poured at the Macondo well -- the first indicated that the foam slurry design was unstable, according to the letter. The final test -- conducted using a modified testing procedure -- showed that the foam would be stable, the letter said.

"Taken together, these documents lead us to believe that 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," according to the letter.

But "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," according to the letter.

Halliburton provided data from one of the two February tests to BP in a March 8 email, according to the letter. But the data appeared in a technical report along with other information. "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."

In September, BP concluded that the nitrogen-cement mix likely didn't hold, based on testing conducted by CSI Technologies in Houston. But the lab had to test a foam similar to what was used in the Macondo well because Halliburton declined to provide a similar cement mixture.

On Thursday, the spill commission said that it had asked Chevron to conduct another test, this time based on off-the-shelf cement and additives used at the Macondo well that Halliburton had in stock. Chevron's lab personnel "were unable to generate stable foam cement in the laboratory using the materials provided by Halliburton and the available design information.

"Although laboratory foam stability tests cannot replicate field conditions perfectly, these data strongly suggest that the foam cement used at Macondo was unstable," according to the letter. "This may have contributed to the blowout."

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