Trans-Alaska pipeline remains shut down

Petroleum News

The trans-Alaska oil pipeline remained shut down for the third day May 27, as the line’s operator, Alyeska Pipeline Service Co., worked to deal with the results of a May 25 spill at Pump Station 9 near Fort Greely, some 100 miles south of Fairbanks.

The Alaska Department of Environmental Conservation is heading the unified command overseeing the spill response. The agency said May 26 that the spill occurred at approximately 10:30 a.m. May 25 when power failed during scheduled maintenance. Battery backup failed and without power, a reserve tank overfilled and oil spilled out onto a lined secondary containment area. DEC said operators manually closed the valve to stop flow into the tank; the tank is damaged and will have to be drained.

The line had been shut down for six hours for scheduled testing of the fire command system, Alyeska said in a statement, and when the station experienced a power failure at approximately 10:20 a.m. May 25, the tank relief valves opened — something they are designed to do. Tank 190 subsequently overflowed and Alyeska estimates that several thousand barrels of oil spilled to containment.

With the pipeline shut down, North Slope producers were initially prorated to 16 percent of normal production; that level was later reduced to 8 percent in an attempt to allow production to be contained in North Slope tanks until the pipeline resumes operation.

Alyeska said May 27 that it has made significant progress with its spill response at Pump Station 9, with crews drawing down the oil levels in Tank 190 overnight and full power restored to the station.

The company said plans for May 27 included recovery of the spill and decontamination of the containment area, moving toward normal pipeline operations.

Of six steps Alyeska outlined in its response, two have been accomplished, the company said May 27: power has been restored to the 65 kilowatt generator and pump station power has been restored. Work is under way to draw down oil from Tank 190 and recover oil in the tank containment area.

The company said the focus is now on planning for the final steps — starting the pipeline and returning to full operation.

The Associated Press reported May 27 that Alyeska is recovering the oil, although the company reported that cleaning up the gravel in the containment area will take longer, and believes it might be able to restart the pipeline by May 28. l

—The Associated Press contributed to this story