Halliburton Co., the contractor that performed cement work aboard BP’s doomed Deepwater Horizon oil rig, has admitted that it did not perform an important test on the cement that was used to seal the undersea well. The cement’s failure to prevent oil and gas from entering the well has been identified as one of the causes of the April 20 explosion that spawned the massive BP oil spill.
This development is raising a lot of eyebrows, because up until now, Halliburton has been able to avoid most of the blame for the BP oil spill disaster. Halliburton previously blamed BP for failing to heed its advice on the design of the well and failing to do all the necessary tests. BP has pointed the finger at the cement mixture Halliburton used.
According to a report on MSNBC, BP at the last-minute increased the amount of a critical ingredient in that cement mixture. While an earlier test showed the cement was stable, the company never performed a stability test on the new blend. According to Halliburton, a successful test was performed on a cement mix different than the one that was eventually used. Tests that were performed on the mixture used did not include a foam stability test, MSNBC said.
Halliburton’s admission followed the issuance of a letter to the president’s oil spill commission from its chief investigative counsel Fred H. Bartlit Jr. The letter said BP and Halliburton knew weeks before the Deepwater Horizon explosion that the cement mixture they planned to use to seal the new well was unstable but still completed the work, according to MSNBC.
The letter also placed some blame on Transocean, the owner of the Deepwater Horizon rig:
“The oil industry has developed tests, such as the negative pressure test and cement evaluation logs, to identify cementing failures” the letter said, but “BP and/or Transocean personnel misinterpreted or chose not to conduct such tests at the Macondo well.”
According to a Wall Street Journal report, the letter cautioned that the new findings don’t absolve BP of responsibility for the Gulf of Mexico oil spill. It notes that cement failures are relatively common, and points out that the well owner – BP – is responsible for testing the cement and fixing any problems.
However, BP could still benefit if investigators determine that Halliburton’s cement design was at fault, the Journal said. Such a development would make it less likely that BP would be found grossly negligent in the disaster, which would reduce its penalties under federal pollution laws.