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Successful gas storage at CINGSA; storage expansion work on target
Alan Bailey for Petroleum News
Summer operations at the Cook Inlet Natural Gas Storage Alaska facility on the Kenai Peninsula ran smoothly, despite the fact that a major expansion project was being conducted at the facility, Matt Federle, CINGSA director of storage operations, told the Regulatory Commission of Alaska on Oct. 24. And the upgrade project, designed to add 2 billion cubic feet of storage capacity, is on target for completion by the end of the year, he said.
CINGSA plays a vital role in storing excess produced gas during the summer, when Southcentral gas demand is relatively low, and then releasing gas during the winter when demand is high. Without the storage facility it would be impossible for gas deliverability rates to be high enough to meet winter demand for power generation and the heating of buildings.
As is typical, this year's gas withdrawals from the facility dropped significantly in April and May, down to very low levels from mid-May through to mid-September, at which point withdrawals started to climb again. Gas injections moved through a reverse pattern, starting to climb in mid-April and dropping back again in September after peaking in June and July.
Continued well testing Meanwhile, CINGSA has been continuing with its multiyear testing of the capabilities of its wells, to ensure that gas withdrawals from wells do not cause excessive amounts of sand to enter well bores, Federle said. Last winter the facility encountered a significant issue with sand causing production problems with two of the wells. By evaluating the amount of sand ingress at different gas withdrawal rates in the wells at different gas inventory levels, the company can set safe limits to gas withdrawal rates.
At this point, CINGSA has completed the testing for three of its five wells at inventory levels above 5 bcf, while testing still needs to be completed for two wells at inventories between 5 bcf and 8 bcf, Federle said. Currently the maximum capacity of the facility is 11 bcf. Conducting testing at inventories below 5 bcf will depend on a situation in which the inventory falls below that level.
CINGSA has established operating limits for its wells, to prevent a recurrence of last winter's production problems. These operating limits will enable CINGSA to meet its contractual obligations to its customers, Federle indicated. CINGSA operates a comprehensive well integrity program, including pressure and flow monitoring, and drawdown testing, he commented.
Currently, surface space on the well pad is constrained by the operation of a drilling rig that is engaged in the drilling of two new wells, as part of the CINGSA expansion project. As a consequence, CINGSA has been unable to put equipment down the two wells that became sanded last winter, to determine the current levels of sand in the wells. However, the company anticipates being able to check the sanding levels in January or February, Federle said.
The facility expansion project The facility expansion project involves the drilling of two new wells, and the installation of two new gas compressors together with various above-ground facilities, including dehydration facilities. As well as bringing additional storage capacity, the upgrade will enable increased gas deliverability, while the additional gas compressors will allow uninterrupted service for customers during maintenance operations, Federle commented.
Designed to be able to withstand a factor 9.2 seismic event, the construction has required the laying of a massive amount of concrete.
A particular problem in the summer resulted from a major amount of rainfall and a resulting excessive amount of water on the ground causing a delay in some of the work, Federle said.
Federle also commented on the challenges that result from a shortage of logistics services on the Kenai Peninsula, and the impact on the project timeline of delays in shipping loads to the project site. For example, because of delays in the project, a crane had to sit on site unused for a time at considerable expense.
However, despite all of these challenges, the project is expected to be completed on schedule and within its budget, John Sims, CINGSA president, told the commission. Sims commented that a particular issue from a tariff perspective arises from the fact that, while only one of CINGSA's customers, Enstar Natural Gas Co., has been funding the CINGSA facility upgrades, there will be benefits from the upgrades for other customers.
--ALAN BAILEY
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