Leak from 8-inch fuel gas line in inlet

The Alaska Department of Environmental Conservation said in a Feb. 15 situation report that there is a processed dry natural gas leak from a fuel gas line between platforms in Cook Inlet.

DEC said the leak was discovered Feb. 7 by a Hilcorp helicopter flying between Nikiski and Platform A.

The natural gas is processed dry natural gas, 98.67 percent methane, from a line providing fuel gas to four platforms: A, C, Dillon and Baker, DEC said. The exact amount of gas being released is not known. Hilcorp reported that up to Feb. 13 the line pressure was approximately 195 psi, reduced to 185 psi Feb. 14, with an estimated leak rate of 225,000 to 325,000 cubic feet per day.

The 8-inch line is in some 80 feet of water.

DEC said Hilcorp conducted overflights on Feb. 8, 9, 11, 12 and 14 to ensure the gas leak was not increasing in size. The overflights on Feb. 8 and 9 showed continued gas release, but bubbles from the natural gas leak could not be detected Feb. 11, 12 or 14 because of ice pans that cover the affected area. Overflights could not be conducted Feb. 10 or 13 due to weather.

Hilcorp activated a diving company to assess the pipeline damage when the gas release was discovered, but diving is not possible due to unsafe ice conditions in Cook Inlet. DEC said Hilcorp is continuing to monitor the pressure and flow rate on the line to ensure there is no sudden decrease in pressure which would indicate increased leak and is monitoring ice conditions to determine when it will be safe for diving activities. It is also coordinating overflights with wildlife resource agencies to assess potential impacts.

- Petroleum News