BP's cement contractor has agreed to plead guilty to destroying technical evidence related to the 2010 Gulf of Mexico oil spill, the US Department of Justice said.
Halliburton Energy Services, a cement contractor working on the Deepwater Horizon drilling rig that exploded in the Gulf of Mexico after a well rupture in 2010, has admitted destroying results of two computer simulations assessing different approaches to securing the damaged oil well.
It has been reported that the company used the Displace 3D simulation program to perform two simulations prior to the disaster, comparing the effect of using either six or 21 centralisers – metal collars attached to the outside of the casing that maintains the integrity of the well, keeping it centred and stable.
Despite the results not differing substantially, Halliburton recommended using 21 centralisers to fix the well; BP, however, opted to use only six. One of the witnesses for Halliburton, cementing service coordinator Nathaniel Chaisson, had testified during the trial that he was concerned about BP's use of just six centralisers.
The programme manager who carried out the assessments was subsequently instructed to destroy the results, US federal officials have said. Similar incidents reportedly occurred about one month later in June 2010.
"Efforts to forensically recover the original destroyed Displace 3D computer simulations during ensuing civil litigation and federal criminal investigation by the Deepwater Horizon Task Force were unsuccessful," the news release said.
"In agreeing to plead guilty, Halliburton has accepted criminal responsibility for destroying the aforementioned evidence."
According to the news release, Halliburton conducted its own review of the well's design and construction after the blowout, and established a working group to review "whether the number of centralisers used on the final production casing could have contributed".
Halliburton is the third company to plead guilty in the oil-spill case. The company has accepted to pay the maximum fine of $200,000 (£130,000) and will be subject to a three-year probation period. It had further promised to cooperate with the government’s criminal investigation team and pay a $55m (£35.7m) contribution to the national Fish and Wildlife Foundation.
The Justice Department has agreed not to pursue further criminal prosecution of the company or its subsidiaries for any conduct arising from the 2010 spill.
During the trial, Halliburton and BP kept blaming each other for the failure of the cement job sealing the Macondo well. BP then asked a federal judge to sanction Halliburton for allegedly destroying evidence about the role that its cement slurry design could have played in the blowout.
The Deepwater Horizon explosion in April 2010 killed 11 workers and caused one of the biggest natural disasters of the past years.