Tests on cement mixture found it to be unstable weeks before fatal explosion at Deepwater Horizon rig, US investigators told
Halliburton, the US company responsible for the cement that was supposed to seal the well and prevent the fatal blow-out, carried out two tests of the mixture in February.
These indicated that the foam slurry was unstable. Data from one of the tests was emailed to BP on 8 March, the commission said last night. “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,” the panel’s lead investigator, Fred Bartlit, said in a letter delivered to the commissioners.
These results appear to contradict public assurances made by Halliburton after the disaster on 20 April that it had tested the cement before pumping it into the Macondo well and that the tests had indicated that the cement would be stable. Shares in Halliburton initially fell 16% on the news. BP shares are also likely to fall tomorrowmorning when the London stock market opens.
The panel had asked Chevron to test mixture similar to that used in the Macondo well in a laboratory to find out if it was stable. When the results suggested it was not, the panel demanded Halliburton provide the data from its tests.
Two further tests were carried out by Halliburton in April. The results of the first, thought to have been reported internally at the company by 17 April, again showed the mixture was unstable. A second test was carried out which appeared to show the slurry would be stable, but the panel said it did not know if this data was available internally before the cement had begun to be pumped into the well. It said that BP only learnt of the results of this fourth, and only, positive test following the explosion.
The letter concluded: “Only one of the four tests 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.” It added that “Halliburton may not have had—and BP did not have — the results of that test before the evening of 19 April, meaning that the cement job may have been pumped without any lab results indicating that the foam cement slurry would be stable;” and that “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; and Halliburton (and perhaps BP) should have considered redesigning the foam slurry before pumping it at the Macondo well.”
The letter made it clear that the blow-out of the Macondo well, which resulted in the deaths of 11 workers, could not be blamed solely on the quality of the cement. “Cementing wells is a complex endeavour and industry experts inform us that cementing failures are not uncommon even in the best of circumstances.”
BP could not be reached for comment . Halliburton said it was reviewing the panel’s findings. BP itself has identified the cement as one of the main causes of the accident. When BP published its internal report into the disaster, Tony Hayward, the then chief executive, said a “bad cement job” was partly to blame.
BP and the other companies involved in the accident face a host of investigations in the US which are likely to drag on for many years. US president Barack Obama appointed the commission to investigate the accident. It is thought that evidence of any alleged wrongdoing could be passed to the Justice Department, which is already conducting its own criminal probe.
The joint investigation board appointed by the US homeland security and interior departments is also expected to produce a final report in January 2011.
Next week BP will report its third-quarter results, a week later than previously expected.