Halliburton and BP had data weeks ahead of the Gulf of Mexico oil spill that showed the cement mixture the companies used to seal the well was unstable, but did not act on the information, according to a report by the US National Commission investigating the Macondo spill.
Tests performed for the investigative panel by industry experts strongly suggested that a mixture that was identical to the base cement slurry that Halliburton used on the well was not suitable. The deficiency “may have contributed” to the blow-out, which killed 11 men and pumped nearly 5m barrels of oil into the sea.