A top engineer for BP’s doomed Macondo oil well made several contradictory statements Thursday as he defended decisions he and his colleague made to place structures and equipment inside the miles-long hole under the Gulf of Mexico.
Halliburton, the contractor BP hired to pour cement in the notoriously wild well to seal its walls, had warned that more devices called centralizers were needed to reduce risk of an incursion of the kind of gas that eventually blew out, destroyed the Deepwater Horizon rig above, killed 11 workers and set off the worst oil spill in U.S. history.
But BP engineering team leader Gregg Walz testified Thursday that he felt they would be able to get a safe cement seal along the walls of the well by simply spreading out the six centralizers they already had, rather than by increasing the number to 21, as Halliburton suggested.
With Transocean lawyer Brad Brian, Halliburton attorney Don Godwin and Coast Guard Capt. Mark Higgins questioning his logic, Walz said he his colleague John Guide came to the conclusion that simply spreading out the six devices would “honor the modeling” from Halliburton that said 21 were needed.
At first, Walz said Halliburton didn’t raise concerns about the decision to go with fewer centralizers, but under questioning from Godwin, Walz acknowledged that Halliburton engineer Jesse Gagliano came to him in person April 18 to make sure he had seen a report warning of possible severe gas flow if they went with seven or fewer centralizers.
Notes by internal BP investigators, which Godwin read to the board Thursday, said that Walz then went to Guide to warn him about the gas flow issue. Guide previously testified that he never was notified about the gas flow warning and didn’t read the report that Gagliano sent him via e-mail April 18.
Asked about that apparent contradiction Thursday, Walz said he couldn’t remember if what the BP investigators’ notes portrayed was correct.
Walz appeared to twist his testimony when he said a decision to use a special, relatively new type of foam cement made the six centralizers comply with the modeling. Godwin pointed out that the decision to use the special nitrogen-infused cement came in March, well before Halliburton ever ran the modeling in the first place.
Walz said he stood by his decision to use six centralizers because any problems they might have discovered by testing the cement’s integrity could then by fixed with more cement.
But Walz and Guide, who also testified Thursday, were part of a group of BP leaders who subsequently decided not to run the definitive test of cement integrity, called a cement bond log. They had hired a team from contractor Schlumberger and flew them out to the rig to do the test, but it was never done.
The test itself would have cost another $128,000 and taken another two days or so, at a cost of about $1 million a day. Other testimony this week established the well was already $54 million over-budget, and Walz and Guide testified Thursday that BP employees are graded every year based on how much money they save the company.
Walz acknowledged under questioning that BP’s own internal protocols require a definitive test of cement integrity, such as a cement bond log, whenever cement covers less than 1,000 feet above a reservoir of oil. He admitted the Macondo well had only 920 feet of cement there, but he decided that was close enough “to the intent” of the rule, and he said no definitive test of cement integrity was ever done.
Walz arranged for the delivery of 15 additional centralizers to the rig to get up to Halliburton’s recommended number of 21, but decided not to use them when he was told they were the wrong type.
Again, he was contradicted in other testimony. Last month, Kent Corser, who led the well design portion of BP’s internal investigation, told a National Academy of Engineering panel that the centralizers were in fact the correct type and BP leaders on the rig incorrectly reported back to Houston that they were another kind with which the company had experienced problems.
Daniel Oldfather, the contractor from Weatherford who was sent to install the centralizers, testified Thursday that he had the devices with him when he arrived by helicopter April 16, but ancillary equipment he needed to do the job never made it.
Meanwhile, BP had chosen to line the well with a series of telescoping metal casings that the company acknowledged gave them fewer barriers against gas flowing into a side space and blowing out the well.
The internal BP investigation has concluded the gas didn’t get into the well through the sides, but through the center, so it concludes the lining design isn’t a significant factor. But Guide, Walz and others were concerned enough at the time that they considered suspending operations altogether, Walz said. In the end, they chose not to stop work and then chose the cheaper of two options for lining the well’s walls.
In an internal BP document, one of Walz’s employees, Mark Hafle, stated the choice of that well design would save the company as much as $10 million.
Questioning of Guide was limited Thursday. He had already spent a full day on the witness stand, and the panel co-chairman, Coast Guard Capt. Hung Nguyen, asked lawyers to respect that he had voluntarily returned. Nguyen noted Guide must be under a lot of pressure after other BP officials fingered him as the man ultimately responsible for the controversial well plan.
Four key BP employees have declined to testify before the board, with three of them citing their Fifth Amendment right not to incriminate themselves, including Hafle, who testified once and then refused to come back for a second round of questioning.