BP Plc officials overseeing the Macondo well that spewed millions of gallons of oil into the Gulf of Mexico ignored questions about whether safety tests done hours before a fatal blast on the drilling rig were flawed, lawyers for Transocean Ltd. said in a court filing.

Donald Vidrine, the senior BP manager on the Deepwater Horizon rig on April 20, 2010, talked with an engineer about unsatisfactory well tests less than an hour before an explosion killed 11 workers on the rig and sent oil pouring into the waters off Louisiana, Transocean’s attorneys said in a filing tied to a trial set for tomorrow with billions of dollars at stake. Transocean owned the rig and was drilling in a well owned by BP and other partners.

While Mark Hafle, a Houston-based BP drilling engineer, warned Vidrine in a phone call that stability tests on the well might be flawed, “neither man stopped work” at the facility, Transocean officials said in the Feb. 24 filing.

The BP officials allowed crews to continue displacing drilling fluid in the well with seawater, the company’s lawyers said in the filing. Once the fluid was removed, the lighter seawater couldn’t hold back natural gas leaking into the well, which led to the explosion, according to the filing.

The filing came three days before BP, Transocean, the U.S. government and plaintiffs suing over the oil spill are scheduled to begin a trial in New Orleans to apportion blame for the disaster and determine exposure to punitive damages.

$26 Billion

U.S. District Judge Carl Barbier, who will hear the case without a jury, is to rule whether BP should get help from the other firms involved in paying the $26 billion in costs associated with the disaster and its resulting offshore spill, the largest in U.S. history.

Scott Dean, a spokesman for London-based BP, declined to comment yesterday on the Transocean filing. Mitchell Lansden, a lawyer for Hafle, didn’t immediately return a call seeking comment late yesterday.

Vidrine has refused to testify about his actions on the rig, citing medical-related problems. His lawyer, Robert N. Habans Jr., didn’t immediately return phone and e-mail messages yesterday seeking comment on the filing.

The Macondo well blowout sent almost 5 million barrels of oil into the gulf over more than 80 days, according to a U.S. government report issued in September.

The accident spawned hundreds of lawsuits against BP and its partners, including Vernier, Switzerland-based Transocean, and Houston-based Halliburton Co. (HAL), which provided cementing services for the well.

The lawsuits include pollution claims by federal and state governments and consolidated cases brought by thousands of commercial fishermen, seafood processors, property owners and tourism-related businesses.

‘Key Source’

Transocean officials have urged Barbier to force Vidrine to testify, calling him in court filings a “key source of information regarding critical events and operations that occurred immediately prior to the blowout.”

Barbier ruled this month that Vidrine must be examined by an independent doctor to determine whether he should be required to give a deposition in the case.

Hafle also has refused to testify after invoking his constitutional protections against self-incrimination, Transocean’s lawyers said in court filings.

‘Adverse Inferences’

In the filing laying out Vidrine’s call to Hafle the night of the explosion, Transocean’s lawyers asked Barbier to allow them to draw “adverse inferences” against BP during the trial over Hafle’s refusal to testify.

“The fact that BP’s on-shore drilling engineer and well site leader disregarded then negative pressure test results is critical to establishing that key BP personnel failed to stop work despite having knowledge of the unsatisfactory test results,” Transocean’s lawyers said in the filing.

Barbier initially set the first phase of tomorrow’s trial as a limitation-of-liability action under U.S. maritime law. The three-month proceeding was to consider Transocean’s effort to cap its financial exposure over the spill under an 1851 law designed to protect ship owners.

The judge later expanded the trial to include claims of fault for the disaster against all defendants, as well as pollution claims brought by federal and state officials.

The case is In re Oil Spill by the Oil Rig Deepwater Horizon in the Gulf of Mexico on April 20, 2010, MDL-2179, U.S. District Court, Eastern District of Louisiana (New Orleans).

Source: Bloomberg