Leak found Jan. 29 from Swanson River well flow line

Petroleum News Alaska Staff

The Alaska Department of Environmental Conservation said Jan. 29 that a leak was discovered by Unocal Alaska in a Swanson River well flow line at 8:20 a.m.

DEC said Unocal reported that an undetermined volume of produced water-crude mix had leaked from a four-inch underground flow line from well 21-34 at the Swanson River field. Unocal reported the produced water as 92 percent water and 8 percent oil-gas mixture.

DEC said Jan. 29 that the flow line had been shut down, response personnel from the Unocal Swanson River field were mobilizing to find the source of the leak and a “super sucker” vacuum truck was en route from K Beach Road.

Unocal engineers will be reviewing information to provide the best estimate of the amount of produced water discharged. Unocal reported the produced water as 92 percent water and 8 percent oil-gas mixture.

DEC said Jan. 30 that response personnel from the Swanson River field had exposed a section of the pipeline and discovered a 0.105 inch diameter hole in the bottom of the line about five feet from where oil was visible on the surface.

A contractor is already removing contaminated soil, DEC said Jan. 30, and that work will continue. The damaged section of pipeline will be replaced and DEC staff will work with Unocal engineers to determine the cause of the leak. Internal corrosion is suspected.

Well 21-34 is approximately one-quarter mile east of Swanson River and DEC said the leak does not pose a threat to the river. A surface area of approximately 20 feet by six feet appeared stained along the flow line route.