KENAI (AP) -- Unocal has halted production from its King Salmon Platform following the latest in a series of leaks from Cook Inlet oil and gas pipelines.
State environmental conservation officials said droplets of oil floating near the platform for about two weeks originally were believed to have come from the platform but an underwater source actually was to blame.
The platform had been producing about 9,000 barrels of crude oil and 3.6 million cubic feet of natural gas per day, said Unocal spokeswoman Roxanne Sinz. The gas was used as fuel on the platform.
Unocal shut production from the King Salmon Platform on Thursday and flushed the 8-inch diameter pipeline that carries crude oil to Trading Bay. Workers planned to clean the line and flush it again with sea water, then pressure test it with water to check for leaks.
If no leaks are detected in the oil line, workers will check an 8-inch pipeline that brings gas used as fuel on the platform from Trading Bay.
The King Salmon Platform was installed in 1967. The undersea oil pipeline was pressure tested last February as a precaution following a spill from a subsea pipeline serving the Dolly Varden Platform. February tests on the King Salmon pipeline found no anomalies.
According to Alaska Department of Environmental Conservation, oil appears to be bubbling intermittently from a subsea source adjacent to the platform. Late Thursday morning, droplets floated to the surface for about 50 minutes, producing a sheen 20-feet wide and 400-yards long.
Another sheen appeared Friday morning. The sheen, however, has dissipated too quickly for any oil to be recovered, the DEC said. The amount spilled is unknown. There has been no oiled wildlife observed. Water around the platform is about 73-feet deep.
Leslie Pearson, DEC on-scene coordinator, said the oil appears at slack low tide, then disappears when the tide shifts.
The oil could be coming from a leak in the vertical pipe that runs through a platform leg to connect with the line on the sea floor, Pearson said. The vertical pipes can be corroded by the tidal action within the legs, and piping within the legs is difficult to inspect.
Pearson said Cook Inlet Spill Prevention and Response Inc. plans to send a ship to take samples from the sheen. Those could help to identify its source. If there is a leak in the vertical pipe, Unocal will have to devise a strategy to fix it, Pearson said.
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