Fire on the Horizon (16 page)

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 sec
tion 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
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, 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.

CHAPTER ELEVEN

KICKS

Mid-February 2010

Macondo Prospect

Marianas had left the crew of the Horizon a hole eighteen inches wide and encased by steel pipe and cement, extending 3,902 feet below the sea bottom. But they’d also left a hole of a different kind, a financial one. Even before the BOP breakdown and the hurricane, the Marianas had missed every deadline set for it, and after completing less than a fourth of the well, it had used up half the hoped-for budget.

Now it was the Horizon’s turn to try to subdue Macondo.

According to the well plan, the rig’s first task would be to drill 2,500 feet farther and two inches narrower below the existing bottom and line the hole with sixteen-inch-diameter casing.

From its inception about two thousand years ago in China, the process by which human beings have drilled wells has always entailed impressive engineering—often unprecedented. In an astonishing spurt of ingenuity, driven by a desperate desire to retrieve deep deposits of brine water to produce salt—as essential to the
ancient Chinese as oil is to us today—salt miners developed many of the basic strategies used by modern drill hands. They built a derrick of bamboo to support a pulley system that allowed them to raise and drop a bamboo pipe fit with an array of heavy iron drill bits weighing as much as five hundred pounds or more. Several men would stand on a wooden plank set on a fulcrum to raise the drill string, then jump off to let it fall, pulverizing the rock in the well hole. When enough debris accumulated in the well, the drillers would drive down a hollow pipe with a leather flap on the bottom, which acted as a valve. The debris would push up into the pipe, then as the pipe was lifted from the hole, the weight of the debris would push the flap closed, keeping the dirt from falling out the bottom. As the well got deeper, more bamboo segments would be attached to the drill string. If the well walls began to crumble, segments of hollow tree trunks were driven into the hole to act as a casing.

The method used on the Horizon retained an impressive similarity. Bamboo has been switched out for steel in the derrick and the drill pipe, and the drill bits are diamond-encrusted, multi-headed swivels with holes spaced regularly along their extensions that spurt oil-based drilling lubricant called “mud.” Instead of just letting the drill bit fall, the 112,000-pound top drive assembly can spin and drive the drill bit into solid rock at anywhere from 40 to 200 revolutions per minute while exerting a downward pressure of up to 20,000 pounds or more. There are a wide variety of bits for different uses and conditions, but one deep-sea bit, encrusted with synthetic industrial diamonds (diamonds created in a laboratory but with all the hardness of natural diamonds), can cost over a million dollars.