Crawling robot patrols Alaska pipeline’s formerly ‘unpiggable’ pipes
In the trans-Alaska pipeline’s early days there was just a pig, a large projectile sliding through pipe with the flow of crude oil, scraping away corrosion-causing water or waxy buildup.
Then along came the “smart pig,” a high-tech twist on the original version that used magnetic and other forces to inspect the pipe as it drifted down the line, providing updates on the pipeline’s condition from the inside.
Now comes a third-generation “crawler pig,” a robot that in the last year has saved Alyeska Pipeline Services Company tens of millions of dollars, while helping prevent spills that could lead to costly shutdowns of the 800-mile artery carrying Alaska’s economic lifeblood.
The latest gizmo — looking like a no-nonsense version of the Pixar movie robot WALL-E — inspects the once “unpiggable” pipelines that are smaller than the 48-inch main line but still critical to the Alaska pipeline’s operation.
Doing the impossible
Some of those secondary lines, connected to pump stations, have never been inspected because doing so wasn’t possible without a dig that exposed the pipe and increased the risk of accidents.
The issue gained attention in 2011, when an “unpiggable” line, buried underground in concrete at Pump Station 1, sprang a leak.
The result was a shutdown that halted North Slope oil production, costing the state $18 million daily. The leak sparked repairs that remain underway because of the extensive engineering required to install about a half-mile of new, above-ground conduit and because of the importance of Pump Station 1.
“It’s the main place where oil enters into TAPS, and if you don’t have it right you can have a shutdown, so everything we do there is with an abundance of caution,” said Michelle Egan, spokeswoman with Alyeska.
A Russian import
Often decades old, infrastructure in the pipeline system needs regular maintenance to operate properly, so the new pig is an important development, said Lois Epstein, an engineer and board president of public-interest group Pipeline Safety Trust.
“Some infrastructure in Alaska is getting old and wasn’t designed in a way that it could be inspected as frequently as it needs to be,” said Epstein.
The 2011 leak led to an agreement with federal regulators at the Pipeline and Hazardous Materials Safety Administration that Alyeska would replace or remove hazardous liquid pipelines at four pump stations and a relief station that couldn’t be inspected with pigs.
“We originally expected to bring all of them above ground,” for inspection, a circumstance that could have pushed total costs into the hundreds of millions of dollars, said Egan.
That left engineers scrambling for a solution that Google ultimately helped provide.
The machine sports track wheels, two that look like big shoes and a retractable one on top. What appear to be arms contain lasers and electromagnetic sensors to detect wall thickness and metal loss. What could be eyes are cameras and LED lights.
A mutating machine
Brian Carlson, director of pipelines services for Diakont at the company’s U.S. headquarters in San Diego, said any resemblance to WALL-E is purely coincidental. The robot does have a name, RODIS — for Remotely Operated Diagnostic Inspection System.
While the pigs of old went with the flow, this next-gen pig operates in dry, cleaned pipe. But it can turn corners, chimney-crawl vertical pipes, or reconfigure itself to fit various sizes.
It moves too slowly to send down the main pipe — the costs of the delay could be catastrophic for Alaska’s economy. But it sends data instantaneously through an “umbilical” tether extending about half a mile, an advantage over the “smart pig” that stores data for later review, leading to a months-long analysis.
The time saved because pipes don’t have to be moved above ground is huge, Neogi said.
“What could have taken three years to finish a project, we’re able to finish that in two months,” he said.
Alyeska worked with Diakont and PHMSA regulators to allow its use in cleaned-out crude lines in the U.S. Federal approval came last year.
After a successful trial at a decommissioned pump station – where the robot found pipe anomalies “planted” by engineers – the company has completed reviews of secondary pipes at other stations.
The review at Pump Station 3 found no problems, said Neogi.
“Several isolated corrosion pits” have been found in pipes at Pump Station 9 near Delta Junction that are being repaired, Egan said.
The robot has already saved the company at least $70 million, Egan said.
“The beauty of this is the delivery system,” said Neogi. “You can take it right to where your issues are.”
Turning to technology
Neogi said the new tool is one example of how Alyeska has become more open to innovation under Tom Barrett, who became president in 2011 after running PHMSA.
“I think it’s very possible this idea might have died on the vine had we not had the tone at the top to say go ahead and make this happen,” Neogi said.
More innovation will be critical in the future because the pipeline operator faces huge hurdles as production continues to fall, including more water and wax buildup as the flow of crude oil slows.
“If we can’t get more oil, we’ll have to figure out how technology will help with all the massive challenges that come with lower throughput,” Neogi said.
Related stories from around the North:
Canada: Imperial delays oil drilling in Canadian Arctic, Alaska Dispatch News
Greenland: Arctic oil and gas must stay in ground to restrict warming to 2°C says study, Blog by Mia Bennett
Iceland: From Arctic Circle 2013-2014, a big drop in the price of oil, Blog by Mia Bennett
Norway: Norway surpasses Russia as top gas supplier, Barents Observer
Russia: Gazprom drilling ongoing at oil field in Arctic Russia, Barents Observer
Sweden: Sweden’s Greens torn on Vattenfall’s coal mines, Radio Sweden