Fire on the Horizon

by Tom Shroder

  The VIPs arrived at 2:30 p.m., signed in, and were handed the standard issue of rig life: hard hats, gloves, safety glasses, and earplugs.

  BP’s O’Bryan had never been on the Horizon before, so had to sit through a one-hour safety briefing. Transocean’s Winslow, who’d had the briefing before, decided to sit in on it again—he wanted to see if the medic who conducted it had picked up on any of the “improvement opportunities” Daun had given him on his previous visit.

  At the end, all four executives were assigned a lifeboat—a formality, obviously, but it was a requirement, even though they were going to be on the Horizon for less than forty-eight hours.

  Throughout drilling, the well had been maintained in a condition called “overbalanced.”

  This meant that the pressure going down the well, in the form of the weight of the fluids that filled it, was greater than whatever pressure was pushing up from the formation toward the surface. The cement job that had just been completed should have meant that the formation pressure was now sealed off at the bottom of the well. Another seal, this one at the wellhead, had also been installed and pressure-tested that morning. The wellhead seal was a second barrier in case the seal at the bottom failed, but it wasn’t designed to stop a high-pressure event, like a blowout. So it was critical that the cement job at the bottom, the bottom plug, be secure.

  This is what the negative test Jimmy Harrell had insisted on would confirm. Before they removed all the mud that had kept the well safe through the drilling process, they would replace some of it with lighter seawater. Now the well would be “underbalanced”—the downward pressure caused by the weight of fluids in the well would be less than the pressure pushing up from the formation. If the cement job had worked, even in an underbalanced state there would be no pressure coming into the well.

  To save time, Kaluza and the day toolpusher, Wyman Wheeler, decided the negative test would be done in lockstep with the other chores that remained before hauling the riser and BOP back up on deck and leaving Macondo behind. In one drill string’s trip down the well—important because just getting everything down there took hours—they would do the negative test, replace the mud remaining in the riser by seawater, then install the top cement plug regulations required before temporary abandonment.

  Wyman, forty, lived in Monterey, a tiny Louisiana town with no stoplights, no pizza delivery, one school that ran all the way from pre-K through twelfth grade, but more than half a dozen churches. Wyman and his wife Rebecca’s eight- and ten-year-olds attended the town school, as had Wyman a quarter century earlier. Instead of going on to college he went right to work, ending up in the oil fields, and rising to toolpusher on the Horizon.

  Wyman was thoughtful and cautious in his approach. He appreciated the complexity of testing in a well where the only information on what was happening thousands of feet down a black hole had to be deduced from meters, dials, and gauges on the rig.

  To begin the test, the crew lowered the stinger tube into the well to the 3,300-foot depth where they intended to set the top cement plug. The stinger would start spraying spacer, the thick fluid used to prevent the mud from mixing with the seawater that was to follow. As it sprayed into the well, the mud below it compressed, having nowhere to go, and forced the spacer to make a U-turn and head back toward the surface.

  The spacer was gray, dense, and sticky. And there was a lot of it.

  It was actually leftovers from the long war against the crumbling walls of the well: two 200-barrel batches of different types of “lost circulation material,” known, like everything else in the industry, by an acronym. LCM was the thick and pulpy patching material they’d needed from the start in Macondo. When they had finally stopped the bleeding at the bottom of the hole a few days earlier, these two batches—charmingly trade-named Form-A-Set and Form-A-Squeeze—were all that was left.

  Leo Lindner, the Horizon’s drilling fluids specialist, had been told by the BP company man to mix the two together for use as a spacer for the negative test. He’d never seen LCM used that way, and it was more than they needed, about twice as much. But Lindner could understand why BP wanted to use it. Any LCM left over would have to be shipped back to shore. With the workboat filling up on all the displaced mud, another service boat would have to come out to haul it away—more time and money. On the other hand, if it went into the well as spacer, when it came out, federal regulations said it could simply be dumped overboard.

  But Lindner was still unsure about mixing Form-A-Set and Form-A-Squeeze together. Monday night, he poured a gallon of one into a gallon of the other to see if anything strange happened. Nothing really did. So the next day, the 454 barrels of the Set-Squeeze mix was fed into the stinger. As planned, the spacer U-turned and went back up the well, pushing the regular mud ahead of it, out the top of the riser, into the mud pits, from where it was eventually offloaded in a thick hose to the 260-foot-long workboat, the Damon B. Bankston, which had tied up to the side of the rig that morning.

  After all the spacer was in the well, the stinger began pumping seawater behind it. Wheeler and his team planned to pump enough water to push the spacer above the BOP—just barely, by twelve feet. When they believed that had been accomplished, they closed the BOP’s annular preventer—the rubber doughnut that sealed around the drill pipe.

  Theoretically, this would hold all the spacer and mud above the test area, leaving only the weight of water against the upward pressure of the well. If the cement job had sealed properly, the inflow pressure from the formation should be zero, as should the pressure on the drill pipe.

  But that’s not what happened.

  With the annular closed, the drill pipe pressure declined to 273 pounds per square inch, but no further. As the team puzzled over this, they discovered that the mud level in the riser had dropped about fifty barrels, which shouldn’t have happened. That could only mean that the annular preventer had leaked. Nobody mentioned the handfuls of rubber that had been found in the outflow from the well recently. In any case, for whatever reason, some 2,000 gallons of the Form-A-Set and Form-A-Squeeze combination had dropped through the annular into the seawater test area, contaminating it.

  At this point, the test was ruined. Whatever pressure readings they got would have to be interpreted through the noise of the mud that had leaked in. The situation could be rectified, but it would mean starting over, refilling the well with mud, new spacer, and new seawater to reinstate pristine test conditions. Then the annular preventer would need to be resealed, this time tightly enough to make sure nothing could leak back down.

  But only the second part of that happened. The pressure on the annular preventer was increased from 1,200 pounds per square inch to 1,900 pounds per square inch, and the drill pipe line and kill line—the line that bypassed the annular preventer and connected below it into the well—were closed while they all discussed what to do next.

  As they talked, the drill pipe pressure shot up to 1,250 pounds per square inch in six minutes.

  Jimmy Harrell and Randy Ezell ushered the VIPs around the rig on their tour. It became clear that the subject they were most interested in was accident prevention. They had some recent incidents from other rigs in mind, and wanted to see if “lessons learned” from those could apply to the Horizon. They climbed out on the rig floor to see a piece of equipment where, on another rig, a worker had stepped into a twenty-four-inch depression, slipped, fallen, and dislocated a shoulder. They seemed a little disappointed to discover that the apparatus was entirely different on the Horizon. None of the learned lessons could apply.

  Now they asked to go down into the columns, where the Horizon had had the flooding incident in 2008. The BP VIPs, Pat O’Bryan and David Sims, wanted to see what it looked like down there. Daun Winslow and Buddy Trahan asked if they could wander around, put eyes on the area and get a feel for what that had all been about.

  First, though, the VIPs stopped into the driller’s shack. It was standing room only in there. Something obviously int
ense was happening. Daun sidled through the crowd and tapped the driller, Dewey Revette, on the shoulder.

  “Hey, how’s it going, Dewey?” Daun asked. “You got everything under control here?”

  “Yes, sir,” Dewey said.

  Daun sensed something wasn’t quite right. He pulled Jimmy and Randy aside. They were the most senior Horizon hands aboard, and monopolizing them for the VIP tour suddenly seemed like a low priority.

  “Looks like they’re having a discussion here. Maybe you could give them some assistance,” Daun suggested.

  So Daun and the other execs went off to look at plumbing in the columns while their tour guides stayed behind to deal with whatever was going on in the driller’s shack.

  The first thing the drill shack assemblage did after realizing what had happened was to call over to the workboat, the Bankston, and tell its captain, Alwin Landry, that they were shutting down the mud transfer for a while. Landry assumed they were breaking for dinner. But in the drill shack, dinner was the last thing they were worrying about. The debate continued for about an hour. Wyman was convinced the pressure readings were evidence of a problem in the well. Bob Kaluza, the day shift company man, thought otherwise. He argued that the pressure spike on the drill string had been caused by the weight of the mud dropping back down into the test area.

  It was past five, and the night shift guys—Jason Anderson, Wyman’s replacement, and Kaluza’s replacement, Don Vidrine—showed up and joined the discussion. The emerging consensus was that the leak through the annular had caused the pressure spike. But Wyman still felt something was wrong.

  It was now just past 6 p.m. Randy Ezell had been on duty for twelve hours. The VIP meeting he was expected to attend would begin at seven. But Randy told Jason he’d stick around to help them figure out what to do about the negative test.

  “Why don’t you go eat?” Jason said.

  Randy hesitated. “Well, I can go eat and come back.”

  “Man, you ain’t got to do that,” Jason said. “I’ve got this. Don’t worry about it. If I have any problem at all with this test I’ll give you a call.”

  Randy studied Jason closely. He’d known Jason ever since Korea. Jason was not only his top lieutenant; he was one of his closest friends on the rig. Randy felt he could read Jason just by his body language, and now what he saw was confidence. He had no doubt that Jason had what it took to deal with the situation, and would be as good as his word and call at the first sign of trouble.

  “Well, maybe I will go eat then,” Randy said.

  He would never see Jason again.

  The night crew decided to conduct a second negative test. They were still debating how do to it when Vidrine pointed out to Kaluza that his shift had ended an hour earlier, and suggested he get out of there and get some rest. You can call Houston on the way out and let them know where we’re at, Don told him.

  Bob went off. But a few minutes later he was back.

  Don did a double take. “Bob, what are you doing here? Go on to bed.”

  Bob shook his head. “No, he told me to come back and stay with you for the negative test. He wanted both of us up here.”

  It was a tricky situation. Their problem was that the heavy spacer that had infiltrated the test area was creating pressure that registered on the drill pipe. That pressure would mask any pressure flowing into the well from the hydrocarbon deposit, which defeated the purpose of the negative test.

  But they thought they had a way to get around that. Instead of using the drill pipe to conduct the negative test, they could use the kill line. The kill line connected at the bottom of the BOP, beyond the seal on the annular preventer, but still several thousand feet above the end of the drill pipe, where the leaked spacer was wreaking havoc. The pressure created by the weight of the spacer should have no effect on the kill line—which meant if they did see pressure on the kill line during the test, it would have to be coming from formation pressure pushing into the well.

  They began by releasing the pressure that had built up in the system. Based on their calculations, the compression of the liquid around the drill string should result in 5 barrels of backflow out the top after it was opened. The 5 barrels flowed into the tanks, and then kept flowing. In the end, 15 barrels came out. When they closed the valve, the drill string pressure quickly rose back to 790 pounds per square inch, fell, then slowly rebuilt to 1,400 pounds per square inch over thirty-one minutes.

  The results were odd. It wasn’t clear, even with the leaked spacer down in the test area, why the pressure reading should rise, fall, then rise again. But they decided to just focus on the kill line.

  The kill line was opened. Mud flowed and spurted. The pressure released.

  Now they pumped seawater into the kill line to make sure the line was full. Then they opened it again. A small amount of water flowed back out, then the flow stopped. The pressure read zero. They watched for thirty minutes and saw no increase.

  “Go call the office,” Vidrine told Kaluza. “Tell them we’re going to displace the well.”

  Finally, they were ready to declare the negative test a success.

  They were wrong.

  A month later, an analysis of well data would suggest that not only did 50 barrels of heavy spacer fluid leak through the annular preventer and fall into the test area, but the rest of the spacer, more than 350 barrels’ worth, had not been pumped high enough. During the second negative test, the bottom of the spacer level was invading the top of the test area, including the bottom of the kill line. The reason the kill line pressure fell to zero and stayed there may not have said anything about what was happening down the well. It may have meant nothing more than that the kill line had been plugged with a thick and sticky mix of Form-A-Set and Form-A-Squeeze.

  CHAPTER SIXTEEN

  SAILOR TAKE WARNING

  1900 Hours, April 20, 2010

  Macondo Prospect

  As the sun dropped toward the rim of the ocean, the horizon caught fire. A handful of rig crew—the poets among the pragmatists—stopped, as always, to admire the reddish orange glow spreading across the western sky. It never got old, reminding them just how close their work brought them to nature’s immense power. They were more akin to shepherds than factory workers in that way.

  It was the kind of moment Dale Burkeen appreciated. The big bear of a crane operator was just beginning his shift as the horizon launched its nightly light show, and nobody had a better view than Dale, sitting in the cab of his crane, 185 feet above the water. The Horizon was an odd place—the heaviest of heavy machinery, a factory on pontoons, but nonetheless surrounded by an unbroken sweep of ocean wilderness under a dome of the biggest, and often bluest, sky anywhere. He often wished he could share the moment with Rhonda and Timmy. On his last shore leave, Dale had sat on his front stoop, Timmy tucked in the space between his dad’s legs looking like a kangaroo pup in a pouch, wishing he could come to the rig with Dad.

  Dale had promised a camping trip when he returned home as compensation. Now, as he watched the red smolder in the western sky, he missed his family. This day was his and Rhonda’s eighth wedding anniversary, and his thirty-eighth birthday was just four days off. But the celebrations would have to wait.

  If Daun Winslow paused to appreciate the sunset, it didn’t distract him from mentally outlining the upcoming meeting he had arranged for the VIPs and the Horizon’s top managers. It was the main business of this visit, allowing them to get together face-to-face instead of being projected on a video screen. The agenda, meant to be informal, was still rather full. They would review goals for the coming year, talk about maintenance issues and the scheduled drydock renovation of the rig in 2011, reemphasize the need to take a proactive approach in dealing with the danger of dropped objects (maybe they’d even get around to revealing the mystery of what the letters in DROPS stood for). Mention would be made of Randy Ezell’s nomination for a company excellence award (for which Randy would no doubt take a lot of affectionate ribbing). And ther
e would be a presentation honoring the Horizon’s amazing record of safety—those seven years without a single lost-time incident.

  Just before the meeting was to begin, Jimmy Harrell straggled in from the driller’s shack where Daun had left him an hour earlier in intense discussions about the negative test.

  “Everything all right up on the rig floor there? Get everything sorted out?” Daun asked.

  Jimmy gave a thumbs-up.

  After the negative test was declared a success, the annular preventer was opened. The pumps cranked up and began again forcing seawater into the hole to flush out mud and spacer that remained in the riser.

  The pumping continued for nearly an hour, then slowed as the mud handlers watched for the spacer to appear at the surface. As the pumping rate decreased, the flow from the well into the fluid return tanks should have decreased in step. Instead it increased. The return tanks filled rapidly, and a gauge on the driller’s panel registered the increased flow. Amid all the activity, and the security of knowing the well had been sealed, nobody noticed.

  Between 8:58 and 9:10, the volume of mud coming out of the well exceeded the volume of the seawater going in by about 2,400 gallons. When the spacer appeared at the surface, the pumping stopped altogether for five minutes, long enough for a “compliance” contractor to test the material and certify it safe to dump overboard, directly into the ocean. The pressure on the drill pipe steadily increased.

  Jason called over to the Bankston and told the crew to stand by to take on the rest of the mud.

  There would soon be nothing but seawater between the rig and the well.

  Things were winding up on the drill floor. Chris Pleasant, subsea supervisor, looked at his watch. It was 9:10. “Jason, I’m done,” he told the toolpusher. “I need to go work on the BOP crane and get it ready and inspect it to pick up the BOP before—before, you know, we unlatch.”