The Trans Alaska Pipeline, the artery carrying all crude oil produced from the North Slope in Alaska, US, remains closed and Alaska North Slope oil producers have subsequently cut their flow of crude to 8% of normal levels.
There is still no estimate of when the pipeline will reopen, after it was closed on Tuesday 25 May following an unexpected power outage that triggered a spill from an overflowed storage tank at a pump station along the 800-mile pipeline.
The amount of oil spilled from the storage tank has still not been determined.
The 8% rate of flow from North Slope producers ensures that storage capacity at the pipeline's Prudhoe Bay intake station will not be filled until Friday 28 May, Michele Egan, spokeswoman for Alyeska Pipeline Service Co, operator of the pipeline system, comments.
During scheduled maintenance work at Pump Station 9, a site about 100 miles southeast of Fairbanks, power from a backup generator failed, triggering the automatic opening of storage tank safety valves that are supposed to relieve pressure in the main line.
Once the safety valves opened, crude oil overfilled the storage tank, spilling into a lined containment area. None of the oil escaped the containment area, and monitors have found no fumes from the pooled crude oil spreading to the area outside the pump station's tank farm.
Alyeska's major owners are the three major North Slope oil producers: BP, ConocoPhillips and Exxon Mobil.
Picture source: Alyeska Pipeline Service Co. via Alaska Division of Spill Prevention and Response