The Trans Alaska pipeline is seen in this undated handout photograph.HO
The operator of the Trans Alaska Pipeline System, which has been struggling for the past week with a leak in piping at the Prudhoe Bay intake station, said the oil artery will resume normal operations late Sunday or early Monday.
Installation of a bypass line is expected to be completed Sunday evening, after which oil flow will be restarted through the 1,280-kilometre pipeline, said a spokeswoman for the pipeline operator and the Unified Command team responding to the situation.
"The tentative timeline for the pipeline to restart is late tonight or early tomorrow," Alyeska Pipeline Service Co.'s Stefani Bell said Sunday. "This time is tentative and may change."
The current temporary shutdown, which began early Saturday morning, is allowing workers to install a 48-metre) bypass line that will route oil around the leaking section of pipe.
That followed an earlier shutdown that lasted from Jan. 8 to Jan. 11. The system, which normally carries nearly 12 per cent of the nation's domestically produced oil, was forced to stop flowing last Saturday when workers discovered oil leaking from a cement-encased pipe into a building at Pump Station 1, located at Prudhoe Bay.
Oil producers on the North Slope - primarily BP, ConocoPhillips and Exxon Mobil - were forced to reduce output to 5 per cent of normal levels.
To avoid freeze-up and storage problems along the line and in the oil fields, the pipeline restarted operations late on Tuesday, though oil flow was generally kept below a rate of 400,000 barrels per day, compared to the recent average of about 642,000 bpd. During that time, oil was collected as it leaked from the affected pipe into the building.
As of Sunday morning, Bell said, the leak at the original trouble spot had been stopped.
Alyeska had hoped this second shutdown would last for only 36 hours, but the work was taking longer due to bad weather and "because this is such a complex project," Bell said.