Don’t worry, BP and Halliburton will still get their milk and cookies!

Three out of four advance tests the oil services firm Halliburton carried out on a cement mixture used to try to close BP’s Macondo oil well in the Gulf of Mexico showed that the cement would be unstable, according to evidence collected by the National Oil Spill Commission.

Halliburton told BP about only one of those tests before the April 20 well explosion – the data indicated the cement plug would probably not hold, yet BP and Halliburton went ahead with the cementing job, according to the commission.

The only Halliburton lab test indicating that the cement slurry might have contained the high-pressure pool of oil and gas at the bottom of the Macondo well was not available until the night of April 19 at the earliest, the commission staff said in a letter issued Thursday.

At the commission’s request, Chevron carried out independent lab tests of a cement slurry that Halliburton said was the same as that used in the Macondo well. The commission staff said that Chevron reported that “its lab personnel were unable to generate stable foam cement in the laboratory using the materials provided by Halliburton.”