Cleanup efforts in Louisiana. (BP)

BP (NYSE: BP) filed the suit yesterday against the Houston-based oilfield service provider for its role in the blowout in the Macondo well on April 20, 2010. Halliburton (NYSE: HAL) designed a failed cement seal experts say may have allowed explosive gas into the well, causing an explosion on the Deepwater Horizon oil rig.

Halliburton admits its seal failed, but said it was BP's duty to run diagnostics to isolate and solve the issue.

The blowout, which resulted in the worst offshore oil spill in U.S. history, gushed 5 million barrels of oil into the gulf and killed 11 workers.

A BP spokesman told the Journal it wasn't suing Halliburton for a specific amount of money, but for damages up to the total cost of the cleanup. BP took a US$40.9-billion pre-tax charge to pay for the spill, as it posted a $4.9-billion loss for fiscal 2010.

While the filing says Halliburton's “misconduct” was a cause of the accident, Halliburton told the Journal it would “vigorously deny these claims.”

BP has also filed suits against two other contractors who worked on Deepwater Horizon, Transocean Ltd., the rig's owner and operator, and Cameron International Corp., the manufacturer of the blowout preventer, a safety device crucial to the well's operation.