Oil & Gas
TAPS Turns 44
What it takes to keep the oil flowing
By Sam Friedman
Alyeska Pipeline Service Company

he Trans Alaska Pipeline System (TAPS) has already outlived initial expectations by more than ten years, though today it runs at less than a quarter of its peak volume.

The pipeline is still in fundamentally sound shape and has a few maintenance properties that would be remarkable if it was an old car: the pipeline requires a smaller maintenance staff to keep it running than it used to, and it’s gotten safer and less leaky as it has aged.

Part of the reason it has aged so well is that Alaska’s oil pipeline is a highly-regulated piece of industrial infrastructure owned by some of the largest corporations on the planet.

But as the pipeline’s owners review how much to invest in keeping the pipeline running into a sixth decade and beyond, TAPS’ maintenance quandaries sound familiar to anyone who’s ever had to decide how much to invest in an aging, but much-beloved vehicle.

Original Steel
TAPS was built in the late ‘70s when the most popular car in America was the Oldsmobile Cutlass.

Like an old car, the pipeline is primarily made of steel, most of which is still in place. Alyeska Pipeline Service Company workers regularly inspect the pipe looking for signs of corrosion. When they find it, the solution usually doesn’t require replacing the line. Workers add a sleeve to the damaged line to reinforce it, says Betsy Haines, Alyeska’s senior vice president for operations and maintenance. Haines grew up in Anchorage during the pipeline construction boom and has worked as an engineer and manager at Alyeska for more than thirty years.

The company tries to head off damage through frequent inspection and cleaning with the intent of heading off future repair work. “The care and maintenance that we put into it over time has helped extend its life,” Haines says.

Nearly all of the more-than 100,000 sections of elevated and buried pipe are original, she says. The largest new segment is an 8.5 mile reroute north of the Brooks Range built in 1991 to replace a section of corroded pipe.

But while the body of the pipeline hasn’t changed much, looking under the hood one sees lots of shiny replacement parts, most notably inside the pumping stations.

The original turbine-powered pumps were replaced with electric pumps during a major pipeline system revamp called “strategic reconfiguration” that was launched in 2001 and cost more than $600 million. Although a major expenditure, the project represented a small fraction of the original pipeline construction price tag of $8 billion.

Some pump stations have closed entirely. As oil flows decreased, Alyeska mothballed no-longer necessary pump stations and repurposed some into stations for adding heat or cleaning devices to the line. The pipeline had eight pump stations at startup and ten at the height of production. Today four pump stations remain in operation.

The next change is planned for August at Pump Station 7, north of Fairbanks. Pump Station 7 hasn’t been needed for pumping for some time but found a second life in the low-volume era adding heat to the line. The warming is no longer needed because of heat-adding equipment upstream, so this summer crews will direct the line to bypass the pump station.

Maintenance Workforce
It famously took a workforce of nearly 30,000 people at the peak of construction to build TAPS, creating a boomtown environment along the route. While most workers returned home or found other jobs after construction, ongoing work to keep the pipeline running smoothly remains sizable, even as it’s gotten slightly smaller in recent years.

Alyeska’s labor force averaged about 1,000 people through much of the pipeline’s history and the company often ranked among Alaska’s ten largest private-sector employers, according to Alaska Department of Labor and Workforce Development numbers.

In September 2018, the business announced it was reducing its workforce by 10 percent as part of a reorganization, and today Alyeska employs about 740 people in Alaska.

“We have answered some of the uncertainties about how water and wax will perform in our pipeline. Now we are confident on our public website that we can operate down to 200,000 barrels per day. I am confident that if we wanted to, we could go even lower.”
Betsy Haines, Senior VP for Operations and Maintenance, Alyeska Pipeline Service Compan
At the height of the summer construction season, a contract force of 600 to 800 additional people also work on the pipeline system, for a total workforce of about 1,300 people, says Haines.

Alyeska employees do most of the equipment and engineering work that’s directly related to the pipe, pumps, and operation of the Valdez terminal. That leaves many supporting roles for contractors, including security, work on small pipes within facilities, and maintenance of the TAPS right-of-way corridor.

“What we’re doing with the data now is game-changing from what it used to be… In the early days of pipeline inspection we didn’t used to be able to process the millions and millions of indications we get in the pipe fast enough or efficiently enough to really leverage the data.”
Stuart Clouston
Global Product Line Manager Pipeline Inspection
Baker Hughes
Today some of Alyeska’s largest contractors are subsidiaries of Alaska Native corporations: Doyon Security (part of Doyon Limited) provides security along the pipeline corridor, and AES-Houston Contracting Company (an Arctic Slope Regional Corporation subsidiary) provides baseline maintenance. Another major contractor is Louisiana shipbuilder Edison Chouest Offshore, which is Alyeska’s spill prevention and response contractor.
Hilcorp, BP, and the Pipeline
TAPS is poised for a significant transition in 2020 as the largest share of its ownership changes hands under the BP/Hilcorp deal announced in August 2019.

One potential challenge is that Hilcorp will need to demonstrate it can finance major infrastructure work and disaster response for the pipeline, as well as the remediation of the pipeline when it reaches the end of its life. Hilcorp is a much smaller company than BP, and as a privately-held company it doesn’t have to disclose financial information to the public, though state and federal regulators overseeing the proposed deal have access to that information.

Alyeska was formed in 1970 to design, build, and maintain TAPS, which is currently owned by four oil company subsidiaries: BP Pipelines (Alaska), 48 percent; ConocoPhillips Transportation Alaska, 29 percent; ExxonMobil Pipeline Company, 21 percent; and Unocal Pipeline Company, 1 percent.

Under BP’s plan to sell its Alaska assets to Hilcorp, BP’s share of TAPS will transfer to Hilcorp-affiliated pipeline company Harvest Alaska, says Alyeska spokeswoman Katie Pesznecker. With the change, Harvest Alaska will have a seat on the TAPS Owners Committee, joining leaders from ConocoPhillips and ExxonMobil.

Two Baker Hughes field service engineers inspect a magnetic flux leakage (MFL) smart pig prior to deployment. MFL pigs are an important tool for detecting weaknesses in a pipeline.

Baker Hughes

A Safer Pipeline
Unlike an aging car, TAPS has gotten less prone to oil spills as it’s aged.

The pipeline’s first decade was its most turbulent. In the first five years of operation, more than 1,000 barrels of oil spilled per year along the pipeline system. The pipeline averaged dozens of reportable spills annually in those early years, according to Alyeska’s pipeline factbook. But in the last twenty years, it has averaged fewer than three reportable spills each year and hasn’t had a 1,000-plus barrel spill since 2010.

Through bypass piping, Alyeska can handle both incidents and routine maintenance without shutting off the flow of oil for long. The pipeline sometimes goes years without shutting down. Even as the line has undergone pump overflows, wildfires, bullet punctures, and earthquakes (including a magnitude 7.9 in 2002), the oil has not stopped flowing for even as long as a week and has only had to shut down for more than three days a handful of times.

Maintenance from the Inside Out
Pipeline maintenance workers today get detailed diagnostic information from the inside of the pipe by periodically running sensors down the line. Pipeline cleaning devices called “pigs” have been a part of pipeline maintenance since the early days of the oil industry. Alyeska primarily uses orange foam cleaning pigs in TAPS. As they travel, these pigs clean out deposits of water and paraffin wax. Without frequent cleaning, these deposits would become habitats for metal-corroding microbes. Alyeska runs cleaning pigs about once per week.

But pigging isn’t just about cleaning. Alyeska started using a completely new kind of pig in 1988: instrument pigs, which are also known as smart pigs. Instead of collecting debris, smart pigs collect data about where the pipe is corroded or dented. Now, federal regulators require pipeline operators to inspect their lines with smart pigs.

One style of instrument pig looks like a cross between a vacuum cleaner and a rocket ship. It works by analyzing the field generated by an onboard magnet in the steel pipeline. These Magnetic Flux Leakage (MFL) pigs are particularly good at detecting corrosion and geometric problems like dents. A different type of smart pig uses ultrasound to specialize in a third type of pipeline weakness: cracking.

Unlike cleaning pigs, MFL pigs aren’t run through the pipe very often. Houston-based oil field service company Baker Hughes runs MFL tests on TAPS on a three-year rotation.

The smart pigs collect an enormous amount of data as they pass through the pipe: scanning the inside of the 4-foot diameter pipe between Prudhoe and Valdez is the equivalent of scanning every blade of grass on the surface of more than 800 football fields. Today’s smart pigs carry as much as a terabyte of data onboard.

MFL technology has been around since the `60s, and MFL pigs have advanced in incremental steps with better quality sensors and data storage, something like the difference between a standard and high definition television, says Stuart Clouston, the Calgary-based in-line inspection product line leader for Baker Hughes.

In the last five years, some of the most important advancements in pipeline inspections have happened far from the pipelines themselves, instead happening at data centers, where computers are getting better at spotting patterns in the magnetic flux readings that correspond to problems with the line.

“What we’re doing with the data now is game-changing from what it used to be,” Clouston says.

“In the early days of pipeline inspection we didn’t used to be able to process the millions and millions of indications we get in the pipe fast enough or efficiently enough to really leverage the data.

“Now instead of one desktop computer you can have fifty desktop computers working on the same thing,” he says, speaking by analogy to explain the explosion of data analysis power.

Both the increase in resolution and the improvements in data analysis help pipeline managers look farther into the future to identify possible failure points.

“[In-line inspection programs] identify both immediate threats along with potential future issues. It’s really a proactive process to make sure you catch things before they become an issue,” Clouston says. “That’s why most recent developments increase the resolution of the tools. We don’t want smaller and smaller things to get away.”

An elevated section of TAPS; almost all the sections of the 800-mile pipeline are original to the 1974-1977 construction.

Alyeska Pipeline Service Company

800 mile pipeline
An elevated section of TAPS; almost all the sections of the 800-mile pipeline are original to the 1974-1977 construction.

Alyeska Pipeline Service Company

Flyovers and Line Walks
New technology is also shaping the way Alyeska surveys the outside of the pipeline. Applications for unmanned aerial vehicles have proliferated in the last few years.

An early adaptation for unmanned aerial vehicles was depth-of-cover studies. Instead of sending crews on riverboats to inspect remote sections of buried pipe threatened by erosion, Alyeska can now view these spots from air.

“It’s improved the speed, it’s improved the quality, and it’s improved the safety so you don’t have to have people out there doing that kind of work,” Haines says. “There are probably more applications in the years ahead.”

One possible application is long-range drone surveys. In 2019, UAF researchers conducted the first FAA-approved beyond-line-of-sight drone flight in the United States. The flight tested both airspace safety and the use of drones for pipeline inspections. A small quadcopter flew along a three-mile section of the pipeline north of Fairbanks, relying on its own sensors for navigation.

Another type of drone used by Alyeska is an underwater vehicle that inspects the pipeline during floods. A particularly large breakup flood of the Sagavanirktok River completely covered the Dalton Highway on the North Slope in 2015. But the pipeline—which is elevated in this section—didn’t sustain significant damage.

Even as technology gives Alyeska new tools for monitoring the pipeline, direct human inspection remains important. An in-depth inspection known as the “line walk” takes place over the entire 800-mile corridor each summer by teams of workers on foot. Types of pipeline issues that have been observed by line walkers include damage from running water, vehicles, stray bullets, and even bird beaks, Haines says. The year-over-year records from past line walks give Alyeska a detailed look at how the pipeline has changed over time.

Forty More Years?
The actual date that the last barrel of oil will flow through the pipeline is a matter of considerable debate and litigation. Various expert estimates that have been made public in the last decade give the pipeline anywhere from twelve to more than thirty years of life left.

A low-end forecast previously used by Alyeska projected the pipeline would stop running around 2032, based on the physical challenges of running the pipeline at flow rates below 300,000 barrels per day. Meanwhile, an internal BP study cited in a 2010 state court decision estimated the pipeline could remain viable at daily throughputs at 100,000 barrels or lower and could operate well beyond 2049.

Of course, predictions about the pipeline’s longevity have been wrong before.

The pipeline was originally expected to operate for thirty-five years, which means operations would have ceased in 2007. Why has it lasted so much longer?

The pipeline’s lifespan has grown in part because Alyeska engineers have determined that the pipeline can run at lower volumes than previously expected.

“We have answered some of the uncertainties about how water and wax will perform in our pipeline,” Haines says. “Now we are confident… that we can operate down to 200,000 barrels per day. I am confident that if we wanted to, we could go even lower.”

The pipeline’s life expectancy has also extended because of the expansion of North Slope drilling. The Prudhoe Bay oil field was originally estimated at 9.6 billion barrels of oil. Growth at Prudhoe and at subsequent North Slope oil discoveries (along with new technologies for recovering oil) have greatly expanded the amount of total crude TAPS can bring to market.

As of early 2020, more than 18 billion barrels of oil had flowed through the pipeline from both Prudhoe and subsequent North Slope oil fields. Converted to gasoline, that’s enough fuel to drive a 1977 Oldsmobile Cutlass the distance of the equator 300 million times.

Part of the pipeline’s future is beyond Alyeska’s control and will depend on whether new oil fields come online upstream, including proposed developments in the Arctic National Wildlife Refuge and the National Petroleum Reserve–Alaska.

Another part of the pipeline’s future will depend on the pipeline’s minimum flow rate. That will likely be an economics question as much as an engineering one. Alyeska’s plans for operating at low flow rates involve a construction project: building a series of heat systems along the pipe to keep the crude oil warm enough.

Ultimately, the pipeline’s owners will have to ask themselves the same question that any vehicle owner asks when facing a big repair bill for an old car: “Is it worth it?”