Alaska News

Oil pipeline shutdown among longest ever

The shutdown of the trans-Alaska pipeline is likely to extend into a fourth day, making it the third-longest closure in the line's 33-year history. Officials haven't yet announced how or when they intend to restart it, which is challenging in the dead of winter.

About 600,000 barrels of crude oil -- some $50 million worth -- that normally would pulse into the pipeline remain in the ground every day it is shut down. North Slope oil field operators are producing only about 5 percent of their usual amount, or about 30,000 barrels a day.

Every day of the shutdown costs the state of Alaska $18.1 million in oil royalties and taxes at current oil prices, according to the state Department of Revenue. That's money it won't be able to collect this budget year, although eventually, when all the oil is pumped from the ground, the state presumably will get its share. Oil proceeds are the main source of state revenue.

Alyeska Pipeline Service Co., which operates the 800-mile-long pipeline on behalf of oil producers, cut off the flow of oil just before 9 a.m. Saturday after workers discovered crude leaking from a secondary line into the basement of a building at Pump Station 1 on the North Slope. The underground piping system is mainly encased in concrete, but oil flowed into the basement at the point the pipe passes through a wall.

As of 10 a.m. Monday, 18 barrels of oil -- or 750 gallons -- had been recovered from the pump house basement, about double the total as of the day before. Residual oil in the piping or spill path is continuing to seep into the building, the state Department of Environmental Conservation said in a situation report released Monday evening.

The cold weather makes restarting the pipeline a challenge. Oil still in the pipeline is cooling. There are risks that ice could form and wax could build up, causing new ruptures, according to state, federal and Alyeska officials. As of Monday evening, federal and state regulators had not yet signed off on a plan to resume the flow of oil.

"I can say we're pushing pretty hard to get a solution going because crude temperatures are getting colder all the time and we are becoming concerned about wax and ice buildup," Alyeska spokeswoman Michelle Egan said. "If we delay startup for too long, then we run the risk of pushing that wax and ice through the pipe and causing more damage and a longer shutdown."


She said the oil would not flow into the pipeline Monday but beyond that wouldn't rule anything in or out.

"Once we have a pretty good idea of what we have support for, we'll talk about what that looks like, time-wise," Egan said.


According to the DEC, Alyeska is gearing up for a normal restart as well as a more complex cold restart in case of an extended winter shutdown.

Temperatures at Prudhoe Bay were warmer than normal Monday but were supposed to give way to single digits by today.

A cold restart involves additional steps, including "monitoring pipe temperatures, periodically circulating oil through equipment, implementing various freeze-up prevention measures, and installing additional piping and equipment at pump stations and other locations on the TAPS line," according to the Department of Environmental Conservation situation report.

The limited amount of oil being pumped from North Slope fields is being stored in two tanks at Pump Station 1. Together they can hold 420,000 barrels, just two-thirds of what would normally be pumped in a single day. As of Sunday, each was close to half-full, according to Alyeska.

The damaged piping system is intended to move oil to and from pumps that boost oil pressure. The problem area hasn't been pinpointed, although testing so far indicates the leak was in the discharge piping, according to the DEC.

Workers are beginning work to drain the pipe, seal it off and install a 157-foot bypass pipe. Parts are being fabricated in Fairbanks. Alyeska chartered two C-130s to deliver parts and equipment to the North Slope on Sunday and more was supposed to arrive Monday, the DEC said.

Egan said she didn't know the age of this secondary piping system or when it was last inspected but was trying to get more information.


About 200 Alyeska employees and contractors have been working on the spill cleanup, pipe repairs and restart, Egan said. About 65 to 70 are at Pump Station 1 and more than 100 have checked in at the emergency operations center in Fairbanks. Some engineers are in Anchorage.

Alyeska workers have been checking for leaks all along the big pipeline both on the ground and by air, the DEC said.

It's not yet known whether any oil spilled outside of the pump building. Alyeska has not found any oil in the groundwater drainage system around the building.

The longest trans-Alaska pipeline shutdown came in August 1977, just after it began operating. The flow of oil was cut off for 110 hours, or 4 1/2 days, Egan said. That shutdown was also because of a leak in a pump house, according to newspaper reports.

The next longest closure came in May 2010 and lasted for more than 79 hours. Alyeska shut down the pipeline then after oil spilled from a storage tank at Pump Station 9 near Delta Junction.

Another shutdown, after the powerful Denali fault earthquake in 2002, lasted about 66 hours.


The current shutdown will top that after 3 a.m. today. It will pass 72 hours, or three days, as of 9 a.m. today.

Find Lisa Demer online at or call 257-4390.


Lisa Demer

Lisa Demer was a longtime reporter for the Anchorage Daily News and Alaska Dispatch News. Among her many assignments, she spent three years based in Bethel as the newspaper's western Alaska correspondent. She left the ADN in 2018.