Centering the Casing
Standard industry practice is to center the well casing to reduce the risk that channels will form in cement, letting gas flow up the well, according to the letter. BP told Halliburton on April 15 it would use six devices called centralizers on the well, while Halliburton's modeling showed 21 were needed, the lawmakers said.
When an objection was raised, BP's Morel wrote back that it was too late to get more equipment to the rig: "It's a vertical hole, so hopefully the pipe stays centralized," he said.
When 15 units were found in Houston, BP's well team leader Gregory Walz objected. "It will take 10 hours to install them,"
Walz said, according to the letter. "I do not like this."
Halliburton account representative Jesse Gagliano ran a computer model using seven centralizers. His April 18 report on the cementing design said the "well is considered to have a severe gas-flow problem," according to the letter.
The decision to skip the so-called cement bond log, a test to assess the integrity of the seal, "may have been driven by concerns about expense and time," the lawmakers said. Conducting the test using a team from Schlumberger Ltd. would have cost $128,000, while canceling the work was about $10,000, the lawmakers said.
The committee contacted Gordon Aaker, a failure analysis consultant with Engineering Services LLP in Houston, who said it was "unheard of" not to conduct the test and called BP's decision "horribly negligent."
The American Petroleum Institute recommends use of weighted mud to fill a well during the drilling process before cementing, the lawmakers said. The process, which can take as long as 12 hours, lets workers test for gas influxes and eliminate debris.
"BP decided to forego this safety step," Waxman and Stupak said.
BP opted against placing a final piece of equipment to hold the well's casing in place, called a lockdown sleeve, the lawmakers said. The device prevents the casing from floating above the head of the well and letting gases build up.
Both Transocean and Halliburton officials have told committee staff this was a key procedural mistake, the lawmakers said.