Halliburton Admits Skipping Test Before Well Explosion Final mix was never tested By Kevin Spak, Newser Staff Posted Oct 29, 2010 11:16 AM CDT 10 comments Comments The Deepwater Horizon oil rig is seen burning in this April 21, 2010 photo. (AP Photo/Gerald Herbert, File) (Newser) – Halliburton has ‘fessed up to skipping a crucial test on the cement in the Deepwater Horizon rig that exploded in the Gulf of Mexico, the AP reports. The admission was issued late last night, after the presidential commission investigating the spill revealed that tests performed by the company had shown the cement was problematic, and may have caused the explosion. Halliburton conducted four tests between February and April, three of which indicated that the mix would fail. None of those tests, however, were conducted on the final mixture, which was not tested at all. The only test BP ever saw was a February analysis that indicated that the cement could fail, according to the commission. BP recently tested the final mixture as part of its investigation into the spill, and found it flawed, but Halliburton dismissed those results, saying the actual mixture was slightly different.