NEW ORLEANS (AP) -- BP asked a federal judge Thursday to sanction its cement contractor on the ill-fated Deepwater Horizon drilling project, accusing the company of withholding critical evidence that could have been used at the ongoing trial over the nation's worst offshore oil spill.
In a late-night court filing, BP PLC lawyers cited Halliburton's alleged destruction of cement samples as grounds for U.S. District Judge Carl Barbier to rule that the contractor's cement design on the drilling project was unstable before the April 2010 blowout of BP's Macondo well.
A Halliburton lawyer disclosed that the company discovered cement samples last Wednesday at a Lafayette laboratory that weren't turned over to the Justice Department for testing after the spill.
BP says its inability to test the missing samples has harmed its ability to defend itself at the trial, which Barbier is presiding over without a jury.
"Halliburton's conduct has undermined the integrity of these proceedings and severely prejudiced BP and the other parties," BP lawyers wrote.
Earlier Thursday, an attorney from Alabama Attorney General Luther Strange's office told Barbier that the state also plans to seek sanctions against Halliburton over the missing cement samples.
Last week, Halliburton lawyer Donald Godwin said the company believes the newly discovered material has no bearing on the case.
But a plaintiffs' attorney, Jeffrey Breit, countered that the samples are cement a Halliburton employee used for testing of the Macondo well before the disaster.
In an email to the court last week, Halliburton said the newly discovered material was associated with the Kodiak well, which BP also was drilling in the Gulf.
On Monday, according to BP, Halliburton disclosed that the missing samples had the same chemical composition as the cement blend that was used on the Macondo well.
"Halliburton also admitted that the 'Kodiak well cement' had in fact been brought onshore from the Deepwater Horizon when the rig was at the Macondo well," BP lawyers wrote.
During the trial's opening statements, plaintiffs' attorney Jim Roy said the Kodiak cement contained an additive, a defoamer that "destabilizes and is incompatible with foam cement."
"So why would Halliburton risk using this leftover Kodiak cement on the Macondo well and try to convert it to a foam cement when it had defoamer in it? The evidence will show Halliburton was able to save time and save money by doing so," Roy said.
Barbier heard testimony on Tuesday from Tim Quirk, who was a Halliburton laboratory manager. Quirk said he secured all of the samples he believed were related to the Macondo well in a locker and stored others in a warehouse, never suspecting the recently discovered samples could be related to the case.
"I had no way of knowing," he said.
Thursday marked the 16th day of a trial that is expected to last several more weeks. Barring a settlement, Barbier could decide how much more money BP and its contractors owe for their roles in the blowout, which triggered an explosion that killed 11 rig workers and led to millions of gallons of oil spewing into the Gulf.