Hilcorp installs permanent repair clamp

The Alaska Department of Environmental Conservation’s Division of Spill Prevention and Response said in a May 22 final situation report that Hilcorp Alaska LLC has installed a permanent repair clamp on a fuel gas line between Platform A and Nikiski in Cook Inlet. A leak was discovered in early February when bubbles were observed from a helicopter.

The gas being released was processed dry natural gas used as fuel on four platforms: A, C, Dillon and Baker.

Repairs to the 8-inch pipeline were delayed initially by ice conditions in the inlet, but a temporary repair clamp was installed April 13, stopping the leak. Hilcorp determined that the cause of the leak was a large rock, approximately 3 feet by 10 feet, which had caused a breach in the line 3/16 inch by 3/8 inch.

ADEC said the U.S. Department of Transportation, Pipeline and Hazardous Materials Safety Administration approved the permanent repair plan for the leak May 10. The dive contractor remobilized to the site May 13 to begin permanent repairs and divers successfully completed permanent repairs May 19. Divers returned to the site May 20 and detected no bubbles or leaks, ADEC said.

Hilcorp has provided five extended wildlife observation overflights for state agency personnel using the company’s fixed wing aircraft and also conducted independent wildlife observation flights with a Cook Inlet Spill Prevention and Response Inc. protected species observer and a wildlife professional from International Bird Rescue using a helicopter.

ADEC said no wildlife has been observed in the vicinity of the leak.

Hilcorp has also completed and submitted nine sampling and monitoring reports which ADEC is reviewing.

Divers will finish stabilizing the line and will demobilize after stabilization efforts are complete, ADEC said.

- KRISTEN NELSON