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A close call for Southcentral gas
Severely cold weather coupled with well problems at CINGSA storage facility nearly resulted in curtailment in gas deliveries Alan Bailey for Petroleum News
During recent presentations to the Alaska Legislature John Sims, president of Cook Inlet Natural Gas Storage Alaska, provided information about the issues with gas deliverability from the storage facility during a recent period of severely cold weather in Southcentral Alaska.
On Feb. 6 Sims told the House Energy Committee that on Jan. 14 CINGSA had to notify its customers that, because of sanding in its No. 3 well, the facility had to drop its maximum gas deliverability by 19%. Given the weather temperatures at that time, the drop in deliverability did not present a problem.
However, a week or so later the forecasted temperatures dropped significantly, with customers placing orders for increased gas supplies. As a result, CINGSA put well No. 3 back into operation, albeit at a lower production level than normal, while starting to monitor the wells every 15 minutes to ensure no further drop in deliverability from well No. 3. However, as the weather became colder and gas delivery increased, CINGSA discovered a loss in deliverability from well No. 1, the most prolific well in the facility. At that point CINGSA had to notify its customers that the deliverability capacity of the system had dropped by 30%.
Energy Watch Group activated On Jan. 26, as the cold weather pushed gas delivery requirements towards CINGSA's reduced maximum capability, CINGSA scheduled daily meetings of the Energy Watch Group, a group of Alaska Railbelt energy utilities, gas producers, industrial gas consumers and gas pipeline operators.
"We started going through all the tools in the toolbox that the electric utilities, that the producers, and that ultimately the customers might be able to do, to make sure that we maintain pressure in that gas transmission line," Sims said. A drop in pressure below critical levels would have created huge problems for the gas delivery system.
In addition, the various borough mayors implemented an energy watch campaign, under which consumers might be asked to reduce their energy usage, should Enstar determine that pressure in its transmission lines was at risk of dropping below required levels. And on Jan. 31 Sims asked Matanuska Electric Association and Chugach Electric Association to staff up for the possibility of having to switch from gas to diesel generation at a moment's notice, Sims said.
Voluntary gas use reductions Following requests from Gov. Mike Dunleavy, Joint Base Elmendorf Richardson voluntarily reduced its gas consumption, as did the Municipality of Anchorage offices, Sims told a joint meeting of House and Senate Resources committees on Feb. 7.
In the event, no diesel generation was required, although the gas pressure teetered on the edge of triggering energy watch action for consumers. Then, as the weather warmed up again, the situation improved and the emergency was over.
Sims told House Energy that one of the constraints in clearing sand from a well bore was the availability of a contractor who could pull a heavy subsurface safety valve from the well. However, the required contractor had become available to do the work on Feb.19, he said.
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