A Sea in Flames - Carl Safina [14]
Later question: “Based on industry standard ways of reading negative tests, you’re looking for something pretty simple, right? A zero on the drill pipe and a zero on the kill line; right?”
Dr. John Smith: “Right.”
Q: “And if you don’t see that, you need to be very concerned; right?”
Smith: “Yes.” Dr. Smith further says, “We know there’s all this heavy spacer mud stuff in the well below the blowout preventer. Likely that mixture is what’s going back up into the kill line, holding the pressure back.”
Smith adds, “We’re doing a test with a line that’s got this dense stuff in it. So, the symptoms are a successful test, but the reality is—it’s not a test at all. My opinion.”
In other words: the only reason they’ve got zero pressure showing on the line they’re relying on is that the thick spacer material has gotten in; the line is clogged.
After thirty minutes of staring at zero pressure on the kill line, the team is convinced that they’ve completed a successful negative test. Never mind that the drill pipe has 1,400 psi on it. They’ve convinced themselves that this was due to something Jason Anderson was calling a “bladder effect.”
BP well site leader trainee Lee Lambert was later examined on this point.
Q: “What was Mr. Anderson saying about the bladder effect? Can you tell us?”
Lambert: “That the mud in the riser would push on the annular and transmit pressure downhole, which would in turn be seen on your drill pipe.”
Q: “Was Mr. Anderson explaining why they were seeing differential pressure on the drill pipe versus the kill line?”
Lambert: “Yes.”
Q: “Okay. And did anyone say anything or disagree with Mr. Anderson’s explanation?”
Lambert: “I don’t recall anybody disagreeing or agreeing with his explanation. At the time it did make sense to me. My lack of experience—. After learning things after the incident, it did not make sense to me, because the kill line and the drill pipe are open up to the same annulus, so in theory should see the same pressure.”
Q: “And since then have you had an opportunity to study this so-called ‘bladder effect’?”
Lambert: “I have not found any studies on the bladder effect.”
In September 2010, BP’s internal investigation concluded: “According to witness accounts, the toolpusher proposed that the pressure on the drill pipe was caused by a phenomenon referred to as ‘annular compression’ or ‘bladder effect.’ The toolpusher and driller stated that they had previously observed this phenomenon. After discussing this concept, the rig crew and the well site leaders accepted the explanation. The investigative team could find no evidence that this pressure effect exists.”
After the negative pressure test, Vidrine tells Bob Kaluza, “Go call the office. Tell them we’re going to displace the well.” They’re about to remove their fluid and replace it with seawater. Poised on a mountaintop, over an oil volcano, they’re about to release the brake.
They’re in a bit of a hurry. But what about the cement job; had it cured correctly already? The negative test helped convince them that it had. But that was only because the kill line was clogged and they chose to explain away the pressure they were seeing on the drill pipe.
The industry standard for judging the success of cement work, to best try to ascertain whether the cement is bonding to everything properly, is called a “cement bond log test.” Halliburton, which did the cement job, will later tell a Senate committee that a cement bond log test is “the only test that can really determine the actual effectiveness of the bond between the cement sheets, the formation and the casing itself.”
Of course, because Halliburton did the cement job, its people would like to blame BP for not using the definitive test. They don’t want anyone focusing on their cement itself.
Using sonic tools, a cement