A plan to restart the pipeline long enough to warm the oil tanks and free a stuck pig north of Fairbanks is under consideration.
The pig is in the line between Milepost 419 and 420 near Wickersham Dome and it "could potentially disable critical pump station equipment due to increased ice and wax accumulation if left in place too long," according to a statement issued by Alyeska and federal and state regulators.
"Waiting to restart the pipeline until the bypass line is in place increases the chance of ice formation and wax buildup within the pipeline," the Unified Command said.
The idea is to get the oil flowing long enough to move the pig about 60 miles to Pump Station No. 8 south of Eielson, where it would be removed. A pig is a cleaning device that fills up the 48-inch pipe and flows along with the oil, scraping away the wax that builds up on the sides of the pipe.
A second pig is also in the line near Thompson Pass and is not as much of a concern as the one north of Fairbanks.
The temporary restart would also "help prevent reaching capacity of the Pump Station 1 tanks, which would halt production." North Slope oil wells are producing oil at a low rate and the oil is being stored on the North Slope while the pipeline is down.
"Cold conditions and lowering crude oil temperatures within the pipeline are a serious concern," the industry and government statement said.