A Sea in Flames - Carl Safina [16]
BP’s report will claim that Halliburton’s foamed cement would have broken down in the well. BP will say Halliburton used a mixture containing 55 to 60 percent nitrogen, and that lab results indicate that “it was not possible to generate a stable nitrified foam cement slurry with greater than 50% nitrogen by volume at the 1,000 psi injection pressure.” The investigation team will conclude that “the nitrified foam cement slurry used in the Macondo well probably experienced nitrogen breakout, nitrogen migration and incorrect cement density. This would explain the failure.… Nitrogen breakout and migration would have also contaminated the shoe track cement and may have caused the shoe track cement barrier to fail.”
Of course, BP’s investigation is suspect of pro-BP bias. But even if the BP report is self-serving and finger-pointing, this we do know: the cement did fail.
Just before Halloween 2010, the president’s Oil Spill Commission will make its own explosive announcement: Halliburton officials knew weeks before the fatal explosion that its cement formulation had failed multiple tests—but they used the cement anyway.
On March 8, 2010, Halliburton e-mailed results of one failed test to BP, but sent only the numbers; there’s no evidence that Halliburton specified that the numbers indicated failed testing. BP had overlooked Transocean’s warning of “severe gas flow,” and might also have not understood it had been given information predicting that the cement would fail.
Halliburton altered the testing parameters, but the cement failed several tests. Finally, just days before the blowout, one last test indicated that the cement would remain stable. But Halliburton may not even have received the results of that final test before pouring the cement on April 19. BP definitely did not get notified that one of the formulations tested successfully. In other words, when Halliburton pumped cement into the BP well, both companies apparently possessed lab results indicating that what they were doing was unsafe.
After the blowout, Halliburton will refuse to give its exact cement formulation to BP for independent testing for its September report. But in coming weeks the president’s Oil Spill Commission’s chief counsel, Fred H. Bartlit Jr., will persuade Halliburton to hand over its cement formulation by reminding its officials that anything they withhold from federal investigators will enlarge the Justice Department’s billowing civil and criminal charges. He’ll then ask Chevron to create a batch and test the mixture under various conditions. In all nine tests, the cement formulation will prove unstable. The unstable cement solidifies into a firm indictment of Halliburton and BP liability.
At the stupendous pressures acting upon the oil and gas in the surrounding strata, even small cracks in the cement are enough to allow the flow rates that would send 60,000 barrels of oil a day out of the well.
Something called a “float collar” enters the discussion. These flapping one-way valves were situated far down the well casing. Rig workers had a hard time getting them to close. They may not have sealed properly, and the fact that the oil and gas shot up the well casing indicates that the float collar’s valves also failed.
Having mistakenly concluded that no hydrocarbons are coming into the well, the workers declare success at 7:55 P.M. on April 20.
At 8:02 they begin displacing all the remaining heavy fluids with seawater. This will take over an hour. They know they’re near completion when the spacer comes back up to the surface.
Returning fluids are usually directed into “pits” on the rig. This time, when the spacer reaches the surface, the crew directs the material directly overboard. This was their way, remember, of avoiding the requirement to bring it ashore and dispose of it as hazardous waste. While the material is being dumped overboard, certain flow meters, or “mudloggers,” are bypassed. In fact, they may