Halliburton questions Chevron's cement-testing ingredients

In its lengthy response to findings that a flawed cement slurry may have contributed to the fateful Macondo well blowout in April, cement services provider Halliburton took aim at the nine cementing tests done by Chevron for the national oil spill commission’s investigation.

Lab technicians at Chevron were unable to generate stable foam cement using ingredients provided by Halliburton, suggesting the cement in the Macondo was unstable, according to a letter sent to the commission by a lead investigator on Thursday.

Halliburton, however, said investigators tested off-the-shelf cement and additives, while the company’s own test prior to the blowout were of a unique blend of cement and additives that existed on the rig.

Halliburton said it would provide the exact materials used on the rig, once samples are released to the Marine Board of Investigation. Currently, the materials are under an evidence preservation order issued by the court.

The company also stood by testing it did of the cement formula before the formula was changed at  BP’s behest. It acknowledged that it did not perform a final foam stability test on the new BP-mandated formula.  However, Halliburton blamed BP for not conducting a cement bond long enough to ensure the final slurry was stable. The company also criticized BP’s well design as potentially contributing to the accident, among other possible causes identified since  the accident.

See the company’s full response below.
Final National Commission Cement Testing Oct 28 2010