Alyeska Pipeline Service Co., operator of the trans-Alaska oil pipeline, has issued a report from a study assessing the potential impact of low oil throughput volumes on pipeline operations. As oil throughput in the pipeline declines, as a consequence of declining production from North Slope oil fields, the temperature of the fluids in the pipeline will become progressively lower, causing several problems including the formation of ice inside the line and the deposition of wax on the pipeline walls.
The low flow study has concluded that problems of this type are likely to occur at throughputs of between 600,000 and 300,000 barrels per day. Water will likely separate from the oil at throughputs of 500,000 barrels per day or less, with ice forming, potentially damaging pumps and other equipment at throughputs below 550,000 barrels per day. Throughputs below 350,000 barrels per day could cause soil around buried sections of the line to freeze, causing frost heaves.
Current throughput is around 600,000 barrels per day.
“The study findings make it clear that the technical challenges compound and increase as throughput declines,” said Alyeska President Tom Barrett. “The simplest, most direct and cost effective path to dealing with these challenges is to stop the decline by adding more oil.”
Alaska North Slope crude oil production averaged 604,508 barrels per day in May, down 4.66 percent from an April average of 634,028 bpd. And on more than a dozen days during the month, beginning May 13 and including May 31, production dropped below the 600,000-bpd mark.
See full story in July 3 issue of Petroleum News, available online at 11 a.m., Friday, July 1 at www.PetroleumNews.com