Updated

BP's first witness at a trial over the deadly Deepwater Horizon disaster testified Monday that he believes the company safely drilled its Macondo well in the Gulf of Mexico before an April 2010 blowout triggered the nation's worst offshore oil spill.

Retired LSU petroleum engineering professor Adam "Ted" Bourgoyne Jr., an expert in drilling operations, said crew members and BP supervisors on the rig followed "normal industry practices" before encountering problems as they tried to plug the well.

"I think the well was drilled safely, basically because standard industry practices were followed. There were no major problems that weren't properly handled," he said. "I even noted that they were taking extreme care to follow all the safety procedures with respect to reporting little minor things that happened, like washers falling out of derricks."

Bourgoyne said he disagreed with many conclusions of Alan Huffman, an expert witness for the federal government who testified earlier in the trial. Huffman accused BP of deviating from industry standards and continuing to drill despite clear signs of trouble.

Huffman concluded that BP repeatedly failed to drill with a "safe drilling margin," which he defined as the cushion between the well's mud weight and its fracture gradient. The mud weight must be kept heavy enough to keep fluids from flowing up the well without fracturing the formation that is being drilled.

"One of the things that Dr. Huffman suggested was that the way that the drilling margin was managed presented dangers, extreme danger to the men and women onboard the Deepwater Horizon. Do you agree with that?" BP attorney Mike Brock asked Bourgoyne.

"No, I don't agree with that at all," he responded.

Bourgoyne said he believed the drilling margin allegations had no connection to the blowout.

He also disagreed with Huffman's claims that BP repeatedly misrepresented the well's pressure integrity test results and gave federal regulators a "very false impression" of what was happening during the drilling operation.

"Did your review indicate that BP conducted an appropriate pressure integrity test at each interval where it should be conducted?" Brock asked.

"Yes, they did," Bourgoyne said.

Bourgoyne joined many other experts and government investigations in concluding that crew members and supervisors failed to properly monitor the well and misinterpreted a key safety test just before the blowout.

"They called it a pass when it was a fail," he said of the test. "It was surprising that they called it a pass. I think the data was clearly there."

Two BP well site leaders, Robert Kaluza and Donald Vidrine, are charged with manslaughter in the deaths of 11 rig workers and await a separate trial. Their indictment accuses them of misinterpreting the same test.

Bourgoyne said the BP supervisors and crew members employed by rig owner Transocean Ltd. discussed the test results "as a group" and ultimately "bought into" an alternate explanation for abnormal drill pipe pressure.

"This is very surprising to me, but it happened. And I think it was a group decision," he said. "They had a lot of confidence in one another, and once they made the decision, they were convinced they were right."

U.S. District Judge Carl Barbier is hearing testimony without a jury. Barring a settlement, he could decide how much more money BP and its contractors owe for their roles in the catastrophe.

The first phase of the trial, which has entered its seventh week, is designed to identify causes of the blowout and assign fault to the companies involved. Barbier plans to hold a second phase that examines BP's efforts to stop the spill and quantifies how much oil spilled into the Gulf.

Testimony by BP witnesses is expected to last at least two weeks.