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Dolly Varden ramping
up production on
alternate pipeline
Kristen Nelson
Unocal spokeswoman Roxanne Sinz told PNA Feb. 16 that divers have found the leak which created a sheen approximately 3/10th of a mile west of the Dolly Varden platform early in February.
When sighted at 1:10 p.m. Feb. 5, the sheen was approximately two miles long and one-half mile wide with 25 percent coverage and was described by the Alaska Department of Environmental Conservation as “stringers and softball size patches of light oil.” The department said the oil was barely visible and visible only at slack tides. It appeared to be bubbling up from beneath the surface of the water.
Unocal said that it immediately began pressure testing the platform’s oil and gas pipelines and found no leaks in the gas pipeline. There was a loss in pressure when the oil pipeline was tested, and the leak was found there. The company said the test produced no additional leak because after the sheen was sighted the line had been shut-in and displaced with clean filtered water in preparation for the test.
Divers have gone down, Sinz said, and have found the leak. Photographs and ultrasonic testing are needed before repairs can be done and ice conditions in the inlet forced the divers to come back up before they could complete that work. Agencies approve alternate pipeline use Unocal received work plan approval Feb. 14 from the Department of Environmental Conservation and the U.S. Department of Transportation to transport oil from the platform through the pipeline most recently used to move fuel gas to the platform. That line, Sinz said, had originally been an oil pipeline.
Unocal started to bring the platform back up Feb. 15 and began production Feb. 16. Sinz said production was being ramped up gradually; at full production the platform produces 3,800 barrels of oil per day.
After the leak from the Dolly Varden line, which Unocal estimated at two to 20 gallons of oil and 20 to 158 gallons of produced water, the company began hydrotesting the eight other oil pipelines in Cook Inlet. Six of the lines have been successfully tested, Sinz said; Testing the two remaining lines is weather dependent because the lines are exposed to the air where they come ashore and water could freeze in the lines.
Sinz said the hydrotesting is in addition to Unocal’s on-going pipeline and inspection program, which cost $2.8 million for Cook Inlet area pipelines last year. Unocal operates more than 100 miles of offshore pipelines and approximately 45 miles of onshore gas pipelines in the Cook Inlet area.
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