CINGSA reports on gas storage performance

Cook Inlet Natural Gas Storage Alaska has filed a report with the Regulatory Commission of Alaska providing an overview of the performance between the end of March 2016 and early April 2017 of the company’s gas storage facility on the Kenai Peninsula.

At the beginning of the period the total inventory of gas in the facility amounted to 14.6 billion cubic feet, including both the base gas owned by CINGSA to maintain reservoir pressure and gas stored by CINGSA on behalf of its customers. By October 2016, following the storage by Southcentral utilities of surplus gas supplies during the summer, the gas inventory had risen to 16.6 bcf, including 7 bcf of working gas and with the remaining 9.6 bcf belonging to CINGSA’s customers.

Winter drawdown of the stored gas, as the weather became colder, began on Nov. 16 and continued through most of March 2017. Consequently, the total gas inventory had dropped back to 11.9 bcf by early April, including 7 bcf of working gas and 4.9 bcf of customer’s gas. This appears to indicate that CINGSA’s customers made net withdrawals of 4.7 bcf of gas during the winter period.

The report says that, overall, the storage facility’s wells have continued to operate effectively and that the flow rate performances of two of the wells have improved significantly. However, the deliverability of one well has been impacted by the ingress of water, the report says. Pressure monitoring has indicated that there has been no leakage of gas from the storage reservoir.

When CINGSA was drilling one of the wells for its storage facility the well encountered an unanticipated pocket of gas in a sand body of the Cannery Loop Sterling C sands which the facility uses for its storage reservoir. A dispute over how this unanticipated native gas should be disposed has been appealed to Alaska Superior Court. CINGSA’s report to RCA says that two different techniques used to estimate the total volume of native gas in the reservoir have supported an estimate of 14.5 billion cubic feet.

- ALAN BAILEY