A Sea in Flames - Carl Safina [5]
When you pump drilling fluid down the well, it comes out the bottom of the drill pipe and circulates up between the drill pipe and the wall of the well, and comes back to you. For every barrel of drilling fluid you push down, you’d better get a barrel back. If you get more—that’s really bad, because gas and oil are coming up in your fluid. If you get less—that’s really bad, too. Drillers call it “lost returns.” It means the returning fluid has lost some of its volume because fluid is leaking into the rock and sand of the well’s walls, sometimes badly. Sometimes there are fractures in the rock and the fluid’s going there. When it’s leaking like that, you can’t maintain the right pressure in the well to tamp down the pressure of oil and gas that wants to come up from below.
In a March 2010 incident, the rig lost all of its drilling fluid, over 3,000 barrels, through leaks into the surrounding rock and sand formation into which they were drilling.
BP’s onshore supervisor for this project, John Guide, later testified, “We got to a depth of 18,260 feet, and all of a sudden we just lost complete returns.”
BP’s senior design engineer, Mark Hafle, was questioned on this point:
Q: “Now, lost returns, what does that mean in plain everyday English?”
Hafle: “While drilling that hole section we lost over 3,000 barrels of mud.”
Three thousand barrels is a lot of barrels. At over $250 per barrel for synthetic oil-based mud, that’s $750,000.
A high-risk pregnancy is one running a higher than normal risk for complications. A woman with a high-risk pregnancy needs closer monitoring, more visits with her primary health-care provider, and more careful tests to monitor the situation. If BP can be called the birth parent, this well was a high-risk pregnancy.
Several times, the well slapped back with hazardous gas belches called “kicks,” another indication that the deep pool of hydrocarbons did not appreciate being roused from its long sleep.
At around 12,000 feet, the drill bit got stuck in rock. The crew was forced to cut the pipe, abandon the high-tech bit, and perform a time-consuming and costly sidetrack procedure around it to continue with the well. The delays cost a week and led to a budget add-on of $27 million.
The work had fallen forty-three days behind schedule, at roughly $1 million a day in costs. At a “safety meeting,” the crew was informed that they’d lost about $25 million in hardware and drilling fluid. Not really safety information. More pressure to hurry.
High-risk pregnancy, added complications. On April 9, 2010, BP had finished drilling the last section of the well. The final section of the well bore extended to a depth of 18,360 feet below sea level, which was 1,192 feet below the casing that had previously been inserted into the well.
At this point, BP had to implement an important well-design decision: how to secure the final 1,200 or so feet and, for eventual extraction of the petroleum, what kind of “production casing” workers would run inside the protective casing already in the well. One option involved hanging a steel tube called a “liner” from the bottom of the previous casing already in the well. The other option involved running one long string of steel casing from the seafloor all the way down to the bottom of the well. The single long string design would save both time (about three days) and money.
BP chose the long string. A BP document called the long string the “best economic case.” And though officials insist that money was not a factor in their decisions, doing it differently would have cost $7 to $10 million more.
BP’s David Sims later testified, “Cost is a factor in a lot of decisions but it is never put before safety. It’s not a deciding factor.”
Sims was John Guide’s supervisor. Guide described the long string design as “a win-win situation,” adding that “it happened to be a good economic decision as well.”
Guide insisted that none of these decisions were done for money.
Q: “With every decision, didn’t BP reduce