The New York Times is reporting that the presidential commission investigating the incident has determined that Halliburton knew the cement mixture it provided was not up to the job. While the Times article gives the high points, you should check out the letter to the commissioners from the lead investigator, Fred H. Bartlit, Jr., which the Times has provided on its site.
According to Bartlit, Halliburton conducted four tests of the cement mixture it intended to supply. Only one of those tests resulted in a "stable" result. Although Halliburton is known to have emailed the results of one of the other (failed) tests to BP, "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."
Willful ignorance, unjustified trust, or simple carelessness?
Based on their own independent testing and the documents Halliburton provided to them, the commission's investigators concluded:
Not that this in any way absolves BP or Transocean, the rig's owner:
- 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; and
- Halliburton (and perhaps BP) should have considered redesigning the foam slurry before pumping it at the Macondo well.
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. BP and/or Transocean personnel misinterpreted or chose not to conduct such tests at the Macondo well.In other words, somebody should have known better.
It's a truism that modern manmade disasters are usually the result not of a single failure, but a whole series of them. Deepwater Horizon is clearly such a disaster. And we almost certainly haven't found all the failures yet.