The shutdown of the 800-mile trans-Alaska oil pipeline continued for a second day Sunday as engineers and regulators worked on how to safely get oil flowing again in the dead of winter.
Alyeska Pipeline Service Co. cut the flow of oil to the main pipeline Saturday morning after workers discovered a leak on a secondary line. Alyeska, which operates the line and its pump stations, directed oil field operators to cut production to a minimal level.
The leak was found inside a building near Pump Station 1 on Alaska's North Slope. The building houses booster pumps, which raise and regulate the pressure of crude oil from storage tanks before it gets into the main pipeline. The booster pumps are critical to operation of the main line, Alyeska and state officials say.
Officials had no estimate on when North Slope production would resume.
On Sunday evening, Alyeska was working on a plan to disconnect and seal off the area of damaged piping and install a bypass line to carry oil to the main pipeline, according to a state Department of Environment Conservation situation report.
So far 9 to 10 barrels of spilled oil -- around 400 gallons -- have been recovered from the building's basement, said Alyeska spokeswoman Michelle Egan. The oily mess was one-half to an inch deep on the 30-by-40-foot basement floor. Most of that oil was sucked up by vacuum trucks. It will be injected back into the pipeline.
More may have leaked out from the underground piping system. Alyeska says it won't have a complete picture until it excavates the damaged pipe, which is encased in concrete and buried. There may well be more oil trapped between the leaking pipe and its concrete casing, Egan said.
At this point, there's no sign any oil seeped out of the concrete encasement into the soil, the tundra or the gravel pad around the building, according to Alyeska and state officials.
Several pipes are in the concrete casing, and it's not yet known which one leaked or why. As of noon Sunday, oil still in the pipeline or spill path was seeping into the basement at the rate of a half gallon a minute, the state report said.
The response so far is focused on rerouting pipe and restarting the flow of oil, said Tom DeRuyter of the state Department of Environmental Conservation. A plan to assess the extent of the spill will come in the next few days from Alyeska, he said.
The effort is complicated by the cold. With the pipeline suddenly shut down, the oil already in it is cooling. Alyeska and government regulators are concerned about ice forming in the pipeline, which could cause additional problems when the oil begins flowing again.
"It is extremely important to us when the pipeline gets shut down," DeRuyter said. "There is always the chance there may be a secondary release (spill). We are going to be watching startup and the repair plans very, very closely, and also the assessment of the area around the booster pump building."
About 200 Alyeska employees and contractors are working on the problem, Egan said. Crews are installing temperature sensors at various points. Workers also have opened valves to lessen the chance of ice forming along the trans-Alaska pipeline, she said.
There are two storage tanks at Pump Station 1 and each is about half-full, Egan said. When the pipeline is shut down for a long stretch, production must be curtailed.
Alyeska directed North Slope operators to cut production to about 5 percent of normal. BP, which runs most of the North Slope oil fields, has done that, spokesman Steve Rinehart said Sunday. So had other operators, Egan said.
Normal production from the North Slope fields averages about 630,000 barrels a day. With the shutdown, about 600,000 barrels are staying in the ground -- or $50 million worth of oil, a day.
"While I am relieved, for the moment, that the leak appears to be contained and has not resulted in a release into the environment, I remain concerned about the potential impact both on oil prices and Alaska's economy of even a short-term shutdown of the pipeline," U.S. Sen. Lisa Murkowski said in a written statement Sunday.
She's the ranking Republican on the Senate Committee on Energy and Natural Resources. Last year she requested a safety review of the pipeline. The review is expected to be complete this spring.
Alyeska shuts the pipeline down a few times a year for scheduled maintenance, usually just for a short period with longer planned shutdowns in the summer for major maintenance.
The longest recent emergency shutdown was three days in May, when about 190,000 gallons of oil spilled at a pump station near Delta Junction. A power failure caused valves to a storage tank to open and the tank overfilled.
Find Lisa Demer online at adn.com/contact/ldemer or call 257-4390.