Gulf oil spill: Halliburton employee cautioned BP about well design choices
A Halliburton employee said he warned BP that its design to seal its oil well could fail -- a warning given to BP two days before the well surged out of control and the oil rig atop it erupted in flames.
The testimony, given in Houston on Tuesday at a joint Coast Guard and Interior Department hearing probing the cause of the Gulf of Mexico oil spill, is the latest to show that some personnel were uneasy about the way the oil rig was operating in the days before the Deepwater Horizon exploded on April 20.
On April 18, Jesse Gagliano, a Halliburton technical advisor, sent a document to BP warning that its design to use fewer centralizers, which keep a pipe centered in the bore hole, could result in a “SEVERE” gas flow problem. He said he also talked to BP employees about the risk.
A severe gas flow problem can happen when a cement seals are done imperfectly. Such a flaw in the cementing could allow a dangerous flow of natural gas to burst up from below the seafloor and into the belly of the rig.
The controversial BP plan to seal the well called for a cheaper, and -- according to experts -- less-safe design.
Specifically, Gagliano recommended that BP use 21 devices called “centralizers” in the well, a recommendation BP ignored. The company eventually used only six.
“My best engineering analysis would have been to run 21 centralizers,” Gagliano said.
Centralizers are doughnut-shaped sheaths that surround pipes and keep them from knocking into the side of the well’s outer wall. A properly centered pipe makes it easier to seal the well with a cement mixture, which should reduce the risk of a gas blowout.
Engineers widely agree that using more centralizers is safer than using fewer. But installing the devices takes time and money.
A BP drilling engineer, Brian Morel, wrote an e-mail April 15 defending the use of fewer centralizers, writing, “Hopefully, the pipe stays centralized due to gravity,” adding that “it’s too late to get any more product to the rig.”
Another e-mail, by BP drilling engineer Brett Cocales, four days before the explosion, expressed a note of caution about how more centralizers can be important. But he didn’t press the point.
“But, who cares, it’s done, end of story, will probably be fine,” Cocales wrote.
Gagliano said he received no response from BP regarding his April 18 warning. Under questioning, Gagliano testified that BP did not tell him about its decision to use fewer centralizers, and that he learned about it from Halliburton coworkers.
Gagliano stopped short of saying the decision to use fewer centralizers was “unsafe,” saying it only “increased risk.”
Gagliano said there is a way to verify if the cement job had any problems that could lead to dangerous formations of natural gas. That test, called a “cement bond log,” works with acoustics, like an ultrasound, to uncover defects in the cementing.
BP canceled that test, saving more than $100,000.
If that test showed problems in the cement seals, BP could have gone back and tried to fix the problem.
Federal investigator David Dykes questioned whether Gagliano’s 33-page report was clear enough in making its point about a gas-flow warning. The warning was on page 18 of the report, and there was no executive summary that underlined the important warning.
Some BP managers have testified they weren’t aware of the warning.
BP lawyer Richard Godfrey said that Halliburton, in its report after the cement corking was done, did not warn BP that the job was done improperly and caused any danger. He referred to a Halliburton e-mail that said, “We have completed the job and it went well.”
-- Rong-Gong Lin II in Houston