Alaska North Slope oil producers have cut their flow of crude to 8% of normal levels as the Trans Alaska Pipeline remained closed for a third day, the pipeline operator said today. There is still no estimate of when the pipeline will reopen, after it was closed on Tuesday following an unexpected power outage that triggered a spill from an overflowed storage tank at a pump station along the 800-mile (1287-kilometre) pipeline. The shutdown has not disrupted tanker traffic in Valdez, Alyeska said. 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 sometime tomorrow, said Michele Egan, spokeswoman for Alyeska Pipeline Service, operator of the pipeline system. "This 8% rate gives us enough time until midday Friday," Egan said in a Reuters report. "It doesn't mean we won't go longer than that." The Trans Alaska Pipeline, which runs from Prudhoe Bay to the tanker port of Valdez, is the artery carrying all crude oil produced from the North Slope.
Alyeska's major owners are the three major North Slope oil producers: BP, ConocoPhillips and ExxonMobil. Tuesday's mishaps occurred during some 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, Alyeska and state officials said.
None of the oil has 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 said. Alyeska had made significant progress in restoring operations at the pump station today, Egan said. "Last night we restored power to the station, which is a very important step. We also started to draw down the crude in the tank and prepare for cleanup efforts, and that's another important step," she said.