Halliburton, a major contractor on BP's doomed Deepwater Horizon oil rig, where a fatal explosion led to the worst-ever offshore oil spill, knew that cement used in the project was unstable but went ahead anyway, a US presidential commission on the disaster has found. The report strengthened BP's case that it shares blame for the Gulf of Mexico disaster with its business partners, and shares in Halliburton fell 16 per cent after the findings.
Halliburton conducted four tests on cement used to seal the bottom of the well, two just days before the well was activated. Only one of the tests suggested the cement was stable. BP was told by Halliburton about the findings of one failed test, but it was buried deep in a report.
BP has claimed that cement from Halliburton failed to contain hydrocarbons at the bottom of the well as required, contributing to a build-up of explosive material. BP set that out in its own report last month. When BP was compiling it, Halliburton refused to provide a formula for the cement, or share details of its tests.