February 2010
Block 252, Mississippi Canyon, Gulf of Mexico
Nature provides no shortage of elaborate, even bizarre mating rituals. The fierce head-butting of elk bulls in rut, the four hundred distinct mating chirps of the grasshopper, even the female praying mantis’s habit of decapitating the male during copulation and ingesting his head—all are astonishing in their own right, but they pale in comparison to what happened above the Macondo well on February 9, 2010.
After the Marianas was towed away for repair on Thanksgiving Day, it took some tinkering and horse trading and a few more lost months before Transocean’s drilling schedule could be rearranged and another company asset could be redirected to Block 252 in the Mississippi Canyon. That turned out to be Deepwater Horizon, which was the first available of the twenty-two Transocean ships or rigs capable of drilling in ultra-deep water. The dynamic positioning operator on the Horizon’s bridge input the GPS coordinates of the Macondo wellhead, and the computer pointed the rig in the right direction and fired the thrusters. That part was simple. But after the Horizon reached its destination, things got considerably more complicated.
The Marianas had left Macondo a 3,900-foot-deep, steel-lined hole to nowhere. The well was less than a third completed and topped by a metal funnel that stuck up just above the ocean floor. The assemblage resembled a supersize version of one of those funnel and tube combinations used to pour gas from a five-gallon jug into the empty tank of a stranded car. In this case, the purpose of the funnel, otherwise known as the wellhead, was to receive the protruding 27-inch diameter male end of the 325-ton blowout preventer dangling from the end of a 5,000-foot steel string attached to a vessel bobbing in the waves high above.
To conceive how difficult it is to drop the BOP stack’s connector pipe into the well’s hole, first imagine standing on the observation deck of the Empire State Building and attempting to lower a soda bottle at the end of a 1,200-foot-long string into a garbage can on the sidewalk. It’s extremely windy, and you’re wearing roller skates. Now consider that, with the building encased in clouds, it’s impossible to see the sidewalk, much less the garbage can.
Imagine an observer with a cell phone at the bottom giving directions as the bottle descended. Every motion made by the person on the observation deck would take time to translate down the long string, and the effect on the bottle of his movements interacting with the swirling winds would be virtually unpredictable.
But all of that would be easy compared with what the crew of the Horizon was attempting to accomplish. Instead of a thousand feet of insubstantial air to contend with, they were dealing with 5,000 feet of water exerting 2,300 pounds of pressure on every square inch of surface area. An assistant with a cell phone wearing even the most advanced scuba gear would be dead before he got a fifth of the way to the bottom. Even a nuclear submarine would be crushed like a grape about halfway down. And instead of simply unspooling a string, the Horizon’s drilling crew would have to assemble, piece by piece, 75-foot segments of 19½-inch-diameter steel pipe weighing more than 30,000 pounds each, and feed them slowly through the center of a moving rig.
Before any of that happened, they had to locate the wellhead. This wasn’t as easy as motoring to the coordinates locked into their GPS system. The GPS coordinates referred to a point on the surface of the ocean and were all but useless in locating a precise point 5,000 feet down. For any practical purpose, there was no “straight down” in the Gulf of Mexico. “Straight” was a theoretical concept rendered all but meaningless by the constantly swirling currents and the prodigious distance, just as there was no dropping a bottle on a string “straight down” from the Empire State Building.
But the Horizon could do a lot better than an assistant with a cell phone.
The rig spent a few days over Macondo taking the opportunity to inspect and maintain its nine-year-old blowout preventer, the same one that had launched with the rig from Korea. Not only did the crew’s livelihoods depend on a properly functioning blowout preventer; so too did their lives. But the only time it could be inspected and maintained was when it was on deck between wells.
Once the subsea engineers were satisfied with the condition of the BOP, they got to work on the elaborate preparations necessary before they attempted to lower it to the wellhead. First the marine crew hooked acoustic beacons to the grating of a steel cage about the size of something that might have been used to punish a troublesome prisoner in a Soviet gulag. The cage was then lowered over the side by a large winch spooled with ten thousand feet of umbilical cable. The cable whirred off the spool interminably. It took a full hour before the cage had descended nearly a mile, to one hundred feet above the sea bottom. Finally the winch yanked the cable to a halt. The cage door opened and something very like a giant hermit crab snuck out. This was an ROV, or remotely operated vehicle. The ROV was equipped with powerful head lamps, video camera eyes, and mechanical arms that gave it that crab look. One of the arms had a cutter where a crab’s pincher would be. The other arm had a grabber, which could be manipulated to grasp and use a variety of simple tools, like a scooper, a squeegee, or a pressure washer.
An umbilical cable with the ROV’s power, hydraulic control, and video lines snaked back up to the rig and connected to the ROV shack—basically a shipping container furnished with comfortable chairs, video screens, telephones and, best of all, joysticks. The joysticks not only controlled the ROV’s movements, but also operated the lights, camera, and the machine’s arms.
Being an ROV operator was a video gamer’s dream job—a 3-D entertainment that wasn’t virtual, but real. Not surprisingly, the ROV operators tended to be young video game enthusiasts who could turn the ROVs in intricate loops and work wonders with the mechanical arms. Either that, or they were older men, invariably small in stature, who had gotten wet to drive the submersibles themselves back in the 1990s, when anchored rigs worked comparatively shallow water and the tiny machines were manned. Either way, both the old and the young operators were geniuses at what they did, and the rig would be nearly helpless without them.
For the moment, the ROV’s task was to locate the wellhead and surround it with five sonic buoys that would allow the dynamic positioning operator to pinpoint its exact location relative to the surface. When the ROV emerged from its cage, the operator switched on its sonar. Because of the currents buffeting the crane cable on the trip down, there was no telling where the ROV had ended up, or even what direction it was facing. They watched the sonar screen as the ROV slowly rotated. A blip appeared—almost certainly the wellhead. They switched on the lights and the camera, and drove the submersible in the direction of the sonar blip. The powerful lights on the ROV pushed back the total blackness of the depths. After a few minutes that seemed much longer, the bulk of the wellhead appeared on the screen. The ROV closed the remaining distance and scurried around the wellhead, inspecting it from all angles with its camera. Grasping the pressure-washing tool, the ROV sprayed off the mud that had settled atop the steel. The ROV operator peered at his video screen, looking for the carpenter’s bubbles welded to the wellhead. If the wellhead had sunk unevenly into the mud, the BOP wouldn’t be able to latch on properly, and the whole effort would have been wasted.
When the bubble appeared on the camera, it was squarely within the level lines. All was as it should be. The ROV could swim back to its cage.
Now the Horizon slowly motored a thousand feet north of the wellhead and hovered. The ROV reemerged and focused its cameras on the cage and the acoustic beacons hanging from the side. They were four-foot-tall steel tubes, four inches in diameter, each containing an extremely sensitive underwater microphone, and each spliced to a rope anchored with a cement block. The ROV used one hand to grab the spliced rope and the other to cut the line securing the buoy cylinder to the cage. Then, still grasping the rope, it swam down to the bottom, placed the weight on the seafloor, and let go of the rope. It returned to its cage, the rig moved to another position a thousand feet from the wellhead, and the procedure was repeated until the wellhead was surrounded by a pentagon of sonic buoys.
Only three of the buoys were required for the triangulation that would give an accurate position of the wellhead. The fourth was there in case one of the other sonic buoys stopped functioning, and the fifth was there to back up the backup. Nobody wanted to have to repeat this process.
When all the buoys were in place, the ROV was cranked back to the surface, and the rig’s transponder, hanging from a pole beneath the pontoon, began to ping the five buoys in sequence. With each ping, the lock on their positions grew slightly more precise. The calibration was complex and dependent on water temperature, salinity, and a host of other variables. For it to succeed, the sea had to be completely quiet. If a workboat was tied to the rig delivering supplies, it would be sent out of range; if workers were striking hammers they would be asked to stop. Sometimes a whale would be cruising the region, making an underwater racket. The whale couldn’t be ordered away, of course, so the crew just had to wait for it to leave on its own. Nothing could be allowed to drown out the distant echo of the beacons.
The calibration was painstaking and complex, but the hard part wouldn’t really begin until it was complete.
The first step was to get the BOP in position, suspended above the water over the rig’s “moon pool”—the hole in the center of the rig directly beneath the derrick that might, hypothetically, reflect the moon on a clear night. The crew unbolted the BOP from the deck, where it had been fastened since being hauled up from the last well, sitting on top of a hydraulically powered cart that looked like a half-scale flatcar. Now the cart inched along a track carrying its enormous burden toward the edge of the moon pool, where the tracks took a left turn out over thin air. A gantry rose up to encase the BOP and lock on from either side.
Photographic Insert
Deepwater Horizon, one of the most powerful industrial machines ever built.
Doug Brown at home with his wife, Meccah, and daughter, Kirah. (Courtesy of Doug Brown) Jason Anderson as the “Sea Baby” during the Horizon’s “Shellback” ceremony in 2001. (Tyson Cullum) Dave Young in his dorm at SUNY-Maritime, circa 1995. He expected to sail a ship, not an oil rig. (Cindy Konrad) Captain Curt Kuchta on the Horizon, circa 2009. (Courtesy of Curt Kuchta)
Crane operator Dale Burkeen, who would become one of eleven casualties, with his son, Timothy, and daughter, Aryan. (Courtesy of Janet Woodson)
Daun Winslow, one of the VIP visitors on April 20. (U.S. Coast Guard) John Guide, BP’s well team leader for the Horizon. (U.S. Coast Guard) Randy Ezell, senior toolpusher. (U.S. Coast Guard) Jesse Gagliano, technical advisor for cement work on the Macondo well. (AP Photos) Mike Williams, chief electronics technician. (U.S. Coast Guard) Stephen Bertone, chief engineer. (AP Photos)
The original Deepwater Horizon supervisory crew in 2001, as the rig floated in the harbor at Ulsan, Korea. Doug Brown is the fourth man from the left in the second row. Two of the victims of the blowout nine years later are also pictured: Donald Clark, first on the right, front row, and Jason Campbell, fifth from the right, second row. (Doug Brown)
(Times-Picayune)
The blowout preventer. (Robert Almeida)
The lower marine riser package. (Robert Almeida)
With inexhaustible fuel from the blown-out well, the fires on the Horizon raged for thirty-six hours. (Getty Images)
The Horizon’s helipad is visible in the foreground, directly above the rig’s bridge, and just to the right of the empty lifeboat berths. (Getty Images)
On the morning of April 22, the combined effects of fire and firefighting overcame the Horizon’s ability to float. It listed, then capsized and plunged to the bottom. (AP Photos)
(AP Photos)
The gantry lifted the BOP off the hydraulic cart, then out toward the center of the moon pool, directly beneath the derrick, and held it there. It was the mirror image of a rocket preparing to launch. Instead of emerging from the gantry and soaring toward the moon, it would be descending into the moon pool, then launching into the inner space of the ocean.
While the BOP hung above the water, its connector pipe aiming toward the wellhead, the drilling crew had been readying the first section of riser pipe.
With its dynamic positioning system, the rig was astonishingly capable of keeping itself on location, but the stability couldn’t be perfect, given the ocean’s heaving waves and currents. The steel riser dangling five thousand feet below the rig would need flexibility to manage these forces. So at the top of the BOP, below the first section of the riser, the crew would install a coupling called a flex joint, a substantial steel and rubber coupling that allowed the rig to move off station by a certain amount without damaging the riser or BOP. The flex joint, which alone weighed several tons, was hooked to the top drive—the huge engine block that, during normal drilling operations, slid down the derrick, turning the drill as it drove deeper into the earth.
The top drive was operated by the driller from a small office directly beneath the derrick, called the drill shack. It used to be that the drill shack was a gritty place where the driller manipulated levers and foot pedals to control the top drive from a ratty chair, but in a fifth-generation rig like the Horizon, the driller sat in air-conditioned comfort at an ergonomically designed console, overlooking the drill floor behind a wall of glass. He operated the top drive through the rig’s computer system using a joystick. On his computer screen he could see virtual dials and gauges that were hooked into the rig’s extensive sensory network and told him whatever he needed to know about what was happening on deck or in the well. His need to know was critical. The sensors could alert him to a well that was about to blow out, or one that was crumbling because of too much drilling pressure. It could also give him early warning of a malfunction in the dynamic positioning system.
Besides failure to anticipate a major storm, the two biggest threats to the system keeping the Horizon steadily above the well were either a sudden power blackout or a power surge. In a blackout, the engines would shut off and set the rig adrift. In rarer instances, a computer glitch or mechanical breakdown could ignite a “drive-off”—powering up one or more of the thrusters from 20 percent to 100 percent in an instant, pushing the rig off the well and threatening to rupture the riser.
If for any reason, the rig begins to move out of position, the system signals a warning. At a certain distance, a yellow light goes on—this is 50 to 60 feet from center in 5,000 feet of water. When the light flashes, the subsea engineer will stand by for an emergency disconnect, known as EDS. Drilling will stop and the drill pipe will be pulled up a little to make sure shear rams in the BOP have nice, smooth pipe to cut into rather than the thick joint between pipe sections. Then the driller will watch his panels. At 100 to 120 feet from center, the red light comes on. That’s when there’s no choice. The EDS button has to be pushed to prevent rupturing the riser.
Nobody wants to push the EDS button. A disconnect is expensive—it would take a day or two before the rig could reconnect to the well and get back to work. But failure to disconnect can be even more costly. The BOP could be damaged or destroyed; the whole wellhead could tip over. It could cause a blowout.
Some rigs have a disconnect a year, and others never have one. For the driller, emergency situations are always in the back of the mind, but almost never in the forefront. Day to day, he is mostly concerned with the operation of his most powerful tool, the top drive.
For now, all it had to do was pull the flex joint up the derrick, then lower it atop the suspended blowout preventer. Drill hands in a hydraulic lift rose to the junction of BOP and flex joint, then bolted them securely together with impact wrenches. Another short piece of riser pipe, which would soon be essential, was bolted to the top of the flex joint. The top drive rose a few inches, taking the weight from the gantry, which disengaged and slid back along its track, out of the way. Now the top drive lowered again, until the short riser joint was sticking a few feet above the top of the drill floor.
It was time to install the spider—a heavy scaffolding with legs that spanned the drill floor above the moon pool. The center of the spider fit around the protruding short section of riser pipe, and powerful clamps held it in place. The driller lowered the top drive a few inches, shifting the weight of its load onto the spider, which caught and held. The top drive could be disengaged and raised back up the derrick, leaving half a thousand tons of heavy-duty plumbing hanging seventy-five feet above the Gulf of Mexico from something resembling a daddy longlegs made of steel.
To get this far had taken about six hours. Now they could run the riser.
The Deepwater Horizon had enough riser pipe on deck to run down into seven thousand feet of water. It was stored on the riser deck, a space the size of half a football field immediately aft of the end-zone-sized drill floor. The pipe was stacked twenty feet high in rows against perpendicular stanchions and beneath the riser crane, which hung off an I-beam running port to starboard across the riser deck.
Fresh from the huddle of the pre-job safety meeting, the team deployed. The crane operator climbed up into the crane cab; the deck foreman found a spot where he could see the entire deck at once; the roustabouts strapped themselves into their harnesses, climbed the rungs of the riser deck stanchions, then jumped off onto the stacked pipe and tied off. There, balancing on the top riser pipe, they reached for the crane blocks—there were two, one on each side—and connected one to each end of the first riser section. The crane lifted the pipe to float horizontally above the stacks, then rolled itself to the middle of ship, swaying the pipe until it lined up with the drill floor. Roustabouts grabbed what would become the bottom end of the pipe, seated it on a skate, and hooked it to a winch cable. The winch pulled the pipe on its skate along the drill deck until it was directly beneath the top drive. Now the far end of the pipe was attached to the top drive and was lifted off the deck, rising at an increasing angle until it dangled vertically above the spider.
From here it would be connected to the pipe end clamped in the spider, the spider would release, and the top drive would lower the now dangling section seventy-five feet. Then the end of the new section would be clamped in the spider, the top drive would release, and the process would be repeated seventy times.
But first, they had to wait.
Up to this point the BOP was still dry. Lowering the next section of pipe would put it in the water. The force of the current pulling on the BOP’s enormous mass could push it against the side of the rig or break the spider’s clamps or otherwise create havoc.
To prevent that from happening, the rig would have to be moving exactly with the current as the pipe was lowered, section by section. Careful calculations had been made by the bridge crew. It would take twenty-four hours to run the riser to full depth. If current was running at about a half knot, and the rig motored twelve miles up current, they could drop the BOP in the water and drift with the current as the riser descended. The rig, the BOP, the riser, and the current would all move in unison, and by the time it got to a depth of 5,000 feet, it would be right over the wellhead.
In anticipation, the rig had been under way throughout the preparations. When the rig arrived at the calculated point, one of the marine crew came up on deck and used some low-tech seamanship. He cast his eye around the surrounding sea, looking for a piece of driftwood, a clump of seaweed, anything that drifted in the current. Then he watched it for a few minutes. If the clump and the rig stayed in synch, he gave the driller the thumbs-up and the driller gave the command.
“Let’s get her wet.”
The top drive rode down the derrick until the BOP splashed in the water. Then the driller slammed on the brakes. A crowd stood around the moon pool and watched the protruding pipe for five minutes. It just hung there, straight as an arrow. The driller flicked his joystick and the top drive dropped another ten feet, then stopped again. The riser was still straight down the middle of the moon pool. They were in the clear.
The drift strategy did have one built-in danger. If the captain and chief mate hadn’t plotted carefully, or the crew was working faster than anticipated, the dangling riser could bang into a submerged ridge or subsea mountaintop. The collision, to say the least, would not be healthy for the BOP.
This had been known to happen. A couple of years earlier on the Discoverer Spirit, the drill floor had been making great time, which meant the BOP was hanging farther down than it should have been when the rig passed over a ridge. The ridge was mostly mud, so no real damage was done as the BOP plowed through it, but the stack had be pulled to the surface and inspected. The Transocean captain was so mortified, he submitted a letter of resignation. The company refused the resignation but gave the captain a warning, and instituted a new policy to ensure that no one ever topped his record for the deepest grounding of a ship…ever. So, from then on, whenever a riser was drifting in the current, an ROV would be deployed to hover one hundred feet below the submerged BOP, scouting for obstacles.
Most often the plan was sound, and there was nothing to watch for. The ROV operators would get bored and start looking for sharks. If they spotted one, they’d send out an alert on the PA system, “Turn on your TVs, we got a big, toothy one smiling on the ROV channel.” It was like a scene out of the movie M*A*S*H, and a whole lot more mature than some of the other things that were occasionally sent out over the PA, like turkey calls or amplified farts.
If no sharks showed up, the ROV crew could find other diversions, like the magically shrinking Styrofoam trick: Write a wife or girlfriend’s name on a Styrofoam coffee cup, attach the cup to the ROV cage, send it into the deep. When the ROV was brought back up to the surface, the cup, subjected to extreme pressures from all angles, would return in perfect shape, but the size of a shot glass.
Or maybe someone would have been bragging about the new watch he’d just bought. You could always find out if the ads claiming that some titanium timepiece would keep ticking at any depth are for real. (They aren’t.)
As the ROV swam below, the thrusters were firing only to keep the rig’s bow into the current. If something went wrong with the riser deployment—a wrench broke, the spider clamp jammed—the dynamic positioning would have to be reprogrammed to hold position until the problem was fixed, leaving the riser temporarily vulnerable to the current. To compensate, the rig’s heading and ballast system would be adjusted, intentionally causing the rig to lean to one side, giving the riser room to be pulled at an angle with the current.
Stopping every ten joints to pressure-test the assembly and make sure there were no leaks, it took two twelve-hour shifts before the Horizon arrived above the wellhead. But now that the climax approached, almost everyone near a TV was keeping an eye on the ROV channel for the dramatic conclusion.
The BOP was hung off a couple hundred feet above the wellhead. The calculators were pulled back out to make sure the riser length was as close to perfect as possible. If it was ten feet off, they could install special short lengths of riser called pup joints to make up the difference.
Then it was time to connect “the jewelry”—beginning with a second flex joint at the top of the riser to match the one at the bottom. The two flex joints compensate for the slight horizontal movements of a working rig. But the rig is also subject to the heave of the swelling ocean. For that, they installed the telescoping joint, called a slip joint, a $3 million tube within a tube that can expand or contract up to fifty feet with each passing wave. About a half-dozen thick steel cables called tensioners were then connected to the outer pipe of the slip joint and run up in every direction, to the top of the moon pool and out to the side of the rig, where they were wrapped around two wheels and fed into hydraulic winches set to pull the cable in or play it out, maintaining a constant tension on the top of the riser. If the rig moved up thirty feet, it would play out thirty feet of cable, and when it fell back down, the cable would be retracted. Like a potbellied man’s suspenders, the tensioners kept the riser string from slacking off below the rig.
Now that the jewelry was connected, all five thousand feet of riser and the BOP dangled above the wellhead. All that remained was to drop the bottle in the garbage can.
The ROV operator, the driller and the DPO all were talking to each other on headsets. The rig was oscillating within a six-foot radius above the funnel-shaped wellhead. That motion was being transferred down the riser five thousand feet to the BOP, but there was a delay of as long as a couple of minutes before the shifting force at the surface resulted in a shift in the position of the BOP. The riser string was heaving up and down by as much as ten feet in the waves. As the BOP oscillated above the wellhead, the driller had to pick the exact moment that a downward thrust of the top drive would “land out” the BOP, seating its wellhead connector into the latching mechanism, linking the well, the riser, and the rig as one.
The idea was to wait for the rig to be at top of its rise, then drop the assembly very quickly. As the connector dropped into the wellhead, the driller could lock it in by rotating the top drive, then slack off the weight. But there was only one way to get it right, and many ways to mess up. If the driller dropped the BOP too quickly, it would smash into the wellhead. If he did it too slowly, the rig would rise up again before the BOP could connect. On the plunge that followed, it would jam down on the edge of the funnel. Either way, the collision could damage the BOP or knock the wellhead over. As mistakes go, both were doozies, multimillion-dollar screwups.
And if the driller needed any more performance pressure, a sizable percentage of the crew was watching on the ROV channel.
A latch-up is considered a clean success if a driller locks it in within ten to twenty cycles of heave. Anything more than that is considered a bit of an embarrassment, even though it’s also probably the most common outcome. Maybe one out of a hundred attempts results in some significant damage. A driller who’s thinking about the one-in-a-hundred chance is going to have a hard time keeping his hand steady.
The Horizon heaved in the waves. The driller waited, waited, then made his move. A mile down, a connection was made. The Deepwater Horizon was off to an auspicious start. Everyone aboard had good reason to think the fog of bad luck that had shrouded Macondo had lifted at last.