Increased gas storage pressure approved

Alan Bailey

Petroleum News

The Alaska Oil and Gas Conservation Commission has approved an increase to the maximum pressure in a reservoir used for natural gas storage in Hilcorp Alaska’s Kenai gas field on the Kenai Peninsula. The pressure increase from 300 to 400 pounds per square inch will enable Hilcorp to store more gas in the reservoir.

In 2006 Marathon Oil Co., the previous Kenai field operator, obtained approval to use the depleted reservoir in the Sterling formation pool 6 C1 and C2 sands for gas storage. Marathon and later Hilcorp have used the storage facility to manage their contracted gas supplies, storing excess gas when gas demand is low to later bolster gas supplies when gas demand rises.

Although Marathon originally requested an allowable maximum pressure of 500 pounds per square inch, a pressure that the company said was more than 2,000 pounds per square inch below the level at which fracturing of the reservoir might occur, the company eventually settled on a maximum pressure of 300 pounds per square inch. The company said that this pressure would be more than enough to accommodate proposed gas storage activities.

AOGCC, in a Feb. 22 approval notice, said that storage operations have evolved since Hilcorp became field operator. Hilcorp has been injecting more gas into the reservoir than did Marathon and has been regularly approaching the 300 pounds per square inch limit. Hilcorp asked to increase the pressure limit, so that storage operations can continue unhindered, the commission said. In approving the pressure limit increase, the commission said that the new pressure limit remains a long way below the fracture pressure for the reservoir, and that allowing for more flexible storage operations constitutes a sound engineering and geoscience decision.

- ALAN BAILEY