[Below are excerpts on the Alaskan pipeline from Rust: The Longest War by Jonathan Waldman. This is a great book, yet leaves so many possible rust stories uncovered, that I hope Waldman writes Rust II (or any other topic — will certainly read his next book whatever it is). Alice Friedemann www.energyskeptic.com ]
Officially, Neogi is the pipeline’s integrity manager. He is responsible for keeping the pipeline intact, whole. Most pipeline operators employ integrity managers, but most pipelines are not like the Trans-Alaska Pipeline System. From Prudhoe Bay to Prince William Sound, TAPS stretches eight hundred miles, which leaves Neogi accountable for one of the heaviest metal things in the Western Hemisphere, through which the vast majority of Alaska’s economy flows. Daily, the four-foot steel tube spits out $50 million of oil.
Four technicians from Baker Hughes, the pig’s manufacturer, wrapped up a third day of checking and double checking and triple checking its componentry. Among other things, in the front segment of the pig, between two yellow urethane cups, they checked 112 magnetic sensors mounted in between 112 pairs of magnetized brushes. These sensors would detect the magnetic field induced in the pipe as the pig, propelled by the flow of oil, traveled through it. Given any kind of anomaly in the half-inch steel—a pit, a ding, a thin spot—the field would change, and the sensors would capture this and record it on a hard drive. Inch by inch, the sensors would capture this information; Neogi hoped they would capture all seven billion square inches of the pipe. That’s 1,200 acres. Using all that data, Neogi would determine the most vulnerable spots on the pipeline, dig them up, and repair them before they became leaks.
No matter how extensively the technicians double checked, even the most advanced pig can’t perform its inspection if the wall of the pipe is covered in wax. Wax, a natural component of crude oil, keeps the magnetic brushes and sensors off the steel wall. The consistency of lip balm or mousse, it plugs up caliper arms that measure the shape of the pipe, and snags odometer wheels. Wax renders smart pigs senseless, leaving them blind, dumb, and amnesiac. Nor can a pig survive a violent voyage. Too fast, and sensor heads melt or crack. Too rough, and the magnetizing brushes wear down. Too jarring, and the universal joint between the pig’s two segments comes apart, wires snap, and power to the magnetic flux sensors is cut off. Poof goes the data, months of work, and millions of dollars—leaving engineers with a pipeline in indeterminate condition, regulators unhappy, and the public at risk. Wax accumulates when the oil cools below 75 degrees, and long, slack sections, where the pig can barrel down mountain passes at high speed, manifest themselves when there’s not much oil flowing through the pipe. Neogi was well aware that it was winter, and that the flow of oil through TAPS was as low as it had been. It was not the best of times to pig.
On account of wax and low flow rates, in the last dozen years, half the smart pig runs have failed.
More recently, a pig was sucked into a relief line at a pump station midway down the line. That the relief line was only sixteen inches in diameter, and guarded with pig bars, was not a sufficient deterrent to the forty-eight-inch pig. This has happened at least a half dozen times. When it happened in 1986, and the pipeline was shut down while the pig was extracted, that meant more than a quarter of the nation’s oil wasn’t moving toward California. Pigs have made it all the way to Valdez, Alaska, only to be ingested in relief lines there. Other pigs have damaged the pipeline, or gotten stuck in it and been destroyed during their extraction.
They planned to launch the tool at seven in the morning, exactly twelve hours behind a red urethane pig of lesser intelligence. That pig, like a giant squeegee, was scraping the line clean. It was the last of nine such scraper pigs that, by Neogi’s design, had been shoved down the pipeline in the previous six weeks. Neogi had kept track of how much wax these pigs had pushed out in Valdez, and graphed it. From 1,200 pounds, the mass had dropped to 400. The line was as clean as it was going to get, primed for inspection. It was ready for the smart
For two decades, the Prudhoe Bay oil fields—Sadlerochit, Northstar, Kuparuk, Endicott, Lisburne—have been declining steadily. Yearly, immutably, they produce 5 percent less oil. The result is that TAPS now carries one quarter of the oil it was designed to carry. It comes out of the ground colder than ever and flows more slowly toward Valdez. Crude used to make it to Valdez in four days, as if running seven-minute miles. Now it walks. Enroute, it cools off even more and, as it does so, deposits more wax on the pipeline. A doctor would call the pipeline arteriosclerotic. While a pipeline waxes, its diameter wanes. Declining throughput makes things difficult for Neogi, but it makes them even more difficult for agencies estimating the pipeline’s lifespan.
The pipeline was designed to survive as long as the oil fields. Lest it clog, it must stay warm, which means that it must remain full of flowing oil. In a perverse symbiosis, the pipeline needs the oil as much as the oil needs the pipeline. As a result, while the consortium of agencies that oversees the pipeline has written that it “can be sustained for an unlimited duration,” Alyeska figures that it’ll survive until 2043, and the state of Alaska figures that it’ll expire a bit sooner. Private consultants, hired to estimate the life of TAPS, mention only “the future” and write of “diligent upkeep” in passive sentences. The estimates all couch what nobody wants to say: the pipeline, once the largest privately funded project in America, and one of its greatest engineering achievements, is now an elderly patient in intensive care.
The companies that built the pipeline foresaw such a future and tried to avoid it. In the immediate aftermath of their 1968 oil discovery, they considered every alternative to a pipeline. They considered extending the Alaska Railroad to the North Slope, until they realized that it’d take sixty-three trains, each one hundred cars long, every day, to ship their oil. They considered trucks, calculating that they’d need nearly the entire American fleet in addition to an eight-lane highway. They looked into jumbo jets supplied by Boeing and Lockheed, turning away when it became apparent that their air traffic would exceed the combined air traffic of all the freight in the rest of the country by more than an order of magnitude. They looked into blimps. They commissioned the world’s largest icebreaking cargo ship, and after it got stuck in the Northwest Passage, they seriously considered using a fleet of nuclear submarines to ship the oil, under Arctic ice, to a port in Greenland. Reluctantly, out of alternatives, they settled on a pipeline.
On most other pipelines, “events” or “incidents” or “product releases”—what the rest of us call leaks or spills—are most often caused by third-party damage. By this, the industry means accidents. Heavy equipment is usually to blame; pipeline ruptures are most often caused by collisions with bulldozers and backhoes. On TAPS, since there’s so little construction across the vastness of Alaska, the risk of accidental third-party damage is low. Natural hazards, on the other hand, present threats in abundance. Earthquakes, avalanches, floods, and ice floes all threaten TAPS. But what really keeps Alyeskans up is corrosion. It’s the number one threat to the integrity of the Trans-Alaska Pipeline. On account of that threat, the pipeline was outfitted with the greatest corrosion-protection features of the era. Its principal protection was its coating: paint. As a backup, a zinc strap the size of a wrist (a giant anode) was buried under the pipe. Though TAPS was, boldly, called rustproof, the defense proved insufficient. Like all coatings, the one on TAPS proved vulnerable—but Alyeska didn’t learn quite how vulnerable for a dozen years. When it did, the company beefed up the pipeline’s corrosion protection with 10,000 twenty-five-pound bags of buried magnesium anodes and a cathodic protection system consisting of a hundred-odd rectifiers spitting a low voltage into the pipe.
Because rocks resist current, the cathodic protection system doesn’t work well in rocky areas, leaving corrosion engineers to their final tool: coupons. On the pipeline, a coupon is a one-inch square of steel, connected to it and buried along it, serving as a surrogate. Alyeska has about eight hundred of them. But coupons don’t prevent corrosion; they just help engineers monitor it.
In a way, monitoring is Alyeska’s second line of defense, and Alyeska does a lot of it. Like all major pipelines, TAPS is monitored by leak-detection software, which compares the flow of oil going into the pipeline with the flow coming out the other end, and also scans for sudden pressure drops. But unlike other pipelines, it is also monitored regularly by pilots using infrared cameras to hunt for signals that the hot oil has escaped into the cold Alaskan earth, as well as by “line walkers” who hunt for dark puddles and squishy tundra along the pipeline, and by controllers watching an array of hydrocarbon-detecting and liquid-detecting and noise-detecting sensors shoved into the ground alongside it. And then there are the dozen state and federal agencies looking over the shoulders of the thousand people operating the pipeline, making it the most regulated pipeline in the world.
But because a smart pig is the only way for Alyeska to determine if its pipeline is about to spring a leak before it has actually done so, and because Alyeska operates under more regulatory scrutiny than any other operator, it sends smart pigs down the line nearly twice as often as any other pipeline operator. It employs a smart pig once every three years, and has been doing so since long before federal pipeline laws stipulated it. Thanks largely to smart pigs, TAPS hasn’t suffered a corrosion-induced leak since it began operating in 1977.2 Over its first thirty years, Alyeska reviewed nearly 350 potential threats to the pipeline, including dents, wrinkle bends, weld misalignments, ovalities, gouges, and corrosion pits. The majority of these problems were found with smart pigs.
Keeping the pipe clean has become a priority nearly as great as keeping it whole, because the latter depends on the former. To keep it clean, Alyeska sends cleaning pigs south weekly. The company keeps a fleet of a dozen such pigs at a maintenance yard in Valdez, and in a perpetual relay, these pigs go back and forth: up the haul road, down the line. The managerial pigs—the smart ones—wait patiently while these janitorial pigs stay busy.
Before the last smart pig run, Alyeska sent a janitorial pig south every four days for a month. When these pigs pop out in Valdez, they usually push out ten or twenty barrels of wax. In the pig mobile, they go straight to the pig wash. The wax, a hazardous material, is collected in barrels and shipped out of state. Once, not many years ago, after the pipeline wasn’t pigged for six weeks, a pig pushed out forty-seven barrels of wax. Beneath all that wax, on account of corrosion, the one-billion-pound pipeline loses in the vicinity of ten pounds of steel a year: the same as an old Ford. Most of that metal loss is on the outside of the pipe, where it’s buried. The inside is, well, nicely oiled. The exception is inside pump stations, where the pipe branches through valves and turbines. In deadlegs—hydraulic culs-de-sac, where oil sits stagnant—microbial-influenced corrosion is a threat. If corrosion struck uniformly, such that the pipeline lost metal evenly and consistently, maintaining it would be vastly easier. After a thousand years, 99.999 percent of the pipe would still be there, sans weak spots. But rust doesn’t work like that. It concentrates in relatively few places, begetting more rust. Alyeska responds only to those places that present severe integrity threats. It looks at spots where 35 percent or more of the pipe’s wall thickness is gone, and where metal loss leaves the pipe at risk of bursting, which it determines from a formula developed by the American Society of Mechanical Engineers.
To the pipeline, though, ravens pose a greater threat. Ravens pick at the pipe’s insulation, and then water gets in. Alyeska spent millions installing bands around the seams of the insulation, and the ravens persisted, outsmarting engineers.
the flow of oil through TAPS decreases, pigging will become drastically more difficult. Below 400,000 barrels per day, it will become impossible to tightline Atigun Pass, because there’s only so much oil a controller can store in the tanks at Pump 1 before he runs out of emergency wiggle room. By then, the slack section on Atigun Pass will be over three miles long. Below 350,000 barrels per day, the “slippage factor” of a cleaning pig will prevent it from scraping the line effectively. With the bypass necessary to keep the wax ahead of it in a slurry, there won’t be enough force to push the pig forward. Alyeska will also need to run them more frequently—as frequently as during this run’s cleaning regimen—and this makes controllers nervous. Meanwhile, by 2015, the small percentage of water entrained in the oil will drop out and begin flowing in a separate layer on the bottom of the line. Collecting at a dozen low spots, it could freeze. In so doing, it could disable check valves or halt pigs. At a flow rate of 400,000 barrels per day (expected by 2020), a pig arriving in Valdez could be pushing a slug of water one third of a mile long. Alyeska may need a new type of pig to push out the water, because water will also corrode the pipeline. Compounding matters, lower throughput will make it harder for controllers to detect leaks.
It was the closest that TAPS had ever been to becoming an eight-hundred-mile-long Popsicle. This is Alyeska’s great fear, its “worst-case event.” Declining throughput may necessitate frequent cleaning pigs, complex operating procedures, smarter and tougher pigs, and increased maintenance—but these are nothing compared with the seizure of the pipeline. North Slope crude gels at 15 degrees. It gets so thick that pumps can’t push it. It becomes thixotropic, like quicksand. For whatever reason—a power outage, say—if the oil sits in the line too long, at the wrong time of year, the threat of the big Popsicle looms. In January 2011, the oil cooled to 25 degrees. The threat is critical.
Alyeska’s former president told Congress that at the flow rate expected in 2015, nine winter days of shutdown could spell the ultimate end of the pipeline. If the oil gels, there will be no recovering from it. The threat makes explosions and even leaks seem trivial. It’s a game ender. It’s because of this conundrum that drilling in the Beaufort and Chukchi Seas is of such importance to Alaska, Alyeska, and Alaskans. Those rigs will tie into the Alaska pipeline, feed it their oil. Sure, residents will get annual dividends, and Alaska will receive billions in royalties and taxes that fund pretty much everything in the state. But it’s the long-term future of the state on the table.
The sooner that someone turns around the two-decade saga of declining throughput, keeping the pipeline from turning into a giant Popsicle, the easier those concerned with the integrity of the pipe will sleep. In the meantime, if TAPS leaks for some reason, and the public withholds forgiveness, the resultant delay in offshore drilling could portend the end of the line. That’s what Neogi was implying when he mentioned the impact on future drilling. A big spill could delay offshore drilling in the Beaufort or Chukchi Seas for two decades, and this could spell the end of the line. End of the line would be the end of the state of Alaska, and not exactly beneficial to the economy of the other forty-nine states in the union. Precarious is the future of the pipeline, and high are the stakes in which Neogi and the integrity management crew operate.