A Sea in Flames - Carl Safina [9]
When BP won the lease to this piece of seabed, it held an in-house contest to name it. The winner, “Macondo,” came from the mythical town hewn from a “paradise of dampness and silence” in Gabriel García Márquez’s novel One Hundred Years of Solitude. In the novel, Macondo is an accursed place, a metaphor for the fate awaiting those too arrogant to heed its warning signs. What had seemed a nice literary allusion now carries ominous portent.
More complications. Part of Jesse Gagliano’s task was to model the cement’s likely performance in this well and design a procedure that would get the cement to the proper locations. On April 15, he discovered some problems. This space between the casing and the wall of this well was very narrow. And the previous experience with lost drilling fluid indicated soft walls, requiring a low cement-pumping rate. These conditions contributed to a model predicting that if the casing moved too close to one side of the well-bore wall, drilling fluid could get left behind, creating pockets or channels where the cement would not distribute uniformly. That is, it wouldn’t fill in all of the space it needed to fill.
To prevent a casing from getting too close to one side of a well bore, drillers slip flexible metal spring devices called “centralizers” over the casing so that it will stay centered in the well bore. By keeping the casing centered, centralizers help achieve good, even, thorough cementing between the casing and the well’s geological wall. In this case, BP had six centralizers. That number concerned Gagliano. On April 15 Gagliano e-mailed BP saying he’d run different scenarios “to see if adding more centralizers will help us.”
BP’s Brian Morel replied, “We have 6 centralizers.… It’s too late to get any more to the rig. Our only option is to rearrange placement of these centralizers.… Hopefully the pipe stays centralized due to gravity.”
But Jesse Gagliano continued his calculations. He determined that twenty-one centralizers should create an acceptably safe cement flow.
And it wasn’t really too late. On April 16, BP engineering team leader Gregg Walz e-mailed BP project manager John Guide, saying that he’d located fifteen more centralizers that could be flown to the rig in the morning with “no incremental cost” for transporting them. “There are differing opinions on the model accuracy,” he wrote to Guide, “but we need to honor the modeling.” He added, “I apologize if I have overstepped my bounds.”
The centralizers made the helicopter trip to the rig.
But Guide expressed dismay at these particular centralizers’ design, the addition of new pieces “as a last minute decision,” and the fact that it would take ten hours to install them. He wrote, “I do not like this,” adding that he was “very concerned about using them.”
Walz backed off.
Later that afternoon BP’s Brian Morel wrote to his colleague Brett Cocales, “I don’t understand Jesse’s centralizer requirements.”
Cocales replied, “Even if the hole is perfectly straight, a straight piece of pipe in tension will not seek the perfect center of the hole unless it has something to centralize it.” And then he added this: “But who cares, it’s done, end of story, will probably be fine and we’ll get a good cement job.”
That was on April 16. It seems to suggest a certain willingness to add risk.
That’s not how BP’s managers saw it. Guide later testified: “It was a bigger risk to run the wrong centralizers than it was to believe in the