ANCHORAGE (AP) -- The source of a Cook Inlet oil leak, and the resulting weeklong shutdown of Unocal's Dolly Varden production platform, was traced Thursday to a hole smaller than a quarter-inch in an undersea pipeline.
Divers were able to pinpoint the hole, but ice floating in the inlet made it unsafe for them to conduct further testing that would help Unocal figure out how to fix it, company spokeswoman Roxanne Sinz said.
Until the line is fixed, Unocal will send crude oil through a natural gas line that leads to the platform, Sinz said. It is a former oil line, so Unocal made the switch with minor modifications at either end, she said.
Before the platform shut down for testing, it was pumping 3,800 barrels of oil a day, she said. Oil was flowing through the alternate pipeline Thursday, but production was still ramping up.
Sinz said she couldn't provide a cost estimate for the spill, but said it would run higher than the weeklong loss of oil revenues. After the leak was discovered, Unocal sent crews to test six of its eight undersea pipelines and additional crews to the Dolly Varden platform, she said.
The company will test its remaining two inlet pipelines once the weather warms up, she said. Testing is done by pumping lines full of sea water and gauging the pressure. The last two lines run right up a beach, and the sea water would freeze in winter temperatures, she said.
Officials at first thought a sheen that appeared near the platform on Feb. 5 might have come from the natural gas pipeline that runs between the platform and the Trading Bay production facility on the west shore of the Inlet.
But that line tested clean, and further tests indicated the platform's crude oil pipeline was losing pressure.
Sinz has said the amount of oil believed lost is small, possibly 2 to 20 gallons.
Most of Unocal's Cook Inlet pipelines were built in the 1960s. The newest, connecting the Steelhead platform, was built in 1986. In 1999, a leak in a pipeline to the company's Dillon platform spilled about 460 gallons of oil and created a sheen 10 miles long.
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