FAIRBANKS — Alyeska Pipeline Service Co. will conduct research to determine whether lowering the water content of crude will improve the performance of the trans-Alaska pipeline.
A 25-year decline in Alaska North Slope oil production continues, which means less oil in the 800-mile pipeline, and more problems in transporting it, including additional corrosion.
Oil in 1988 took four days to reach Valdez but now takes 18. The slower flow rate means oil temperature within the line can dip down to 32 degrees.
Alyeska President Tom Barrett told the Fairbanks Daily News-Miner that lowering the water content of the crude in the pipeline may help.
“We think this might be a really good idea, might help us through some of the declining flow issues,” Barrett said.
Testing and evaluation is expected to take at least 18 months.
The flow in the pipeline currently is .22 percent water, Barrett said. At low temperatures, the water becomes ice or “slushy oil.” The water, he said, likely causes a disproportionate amount of the corrosion.
Alyeska engineers want to find out if cutting the water content by half or more will reduce damage.
Studies will begin this summer to simulate pipeline operations at various water-content levels, said Alyeska spokeswoman Michelle Egan.
Engineers also will study what would be needed on the North Slope to remove more water.
Alyeska is taking steps to add heat to the pipeline. Pump Station 5 is being engineered to deliver additional heated oil to the line within two years.
Adding heat, however, carries risks. It has added to waxy buildup on pipeline walls. Egan said.
Company officials say the pipeline can operate at about 300,000 barrels of oil per day but must find new approaches to maintain the flow, Egan said.
“What we’re learning now is that heat isn’t the only solution,” she said.