Xcel uses desert reservoirs to maximize gas efficiency
Deep below the snow-covered adobe hills of the desert north of Grand Junction sits a little-noticed energy bank, one that is regularly emptied and refilled.
What are known as the Asbury and Fruita fields are played-out natural gas reservoirs given new life as storage sites for natural gas.
Xcel Energy Inc. regularly pumps natural gas in the summer into the Asbury and Fruita fields, where the gas waits until the cold winds of winter force prices down and demand for natural gas up.
That’s when Xcel taps the piggy banks. “We tend to fill it across the summer and in later November, we pull the gas out and deliver it from November to March, when peak demand is the highest,” said Curt Dallinger, director for gas resources and planning for Xcel.
Using Asbury and Fruita, which combined can store about 1 billion cubic feet of natural gas, allows Xcel to sell the gas at prices below the winter market, Dallinger said.
Xcel moreover doesn’t have to build expensive new pipelines in order to use and reuse the gas it collects over the low-demand summers, Dallinger said.
Xcel owns gas fields on the Front Range that it uses in a similar manner, Dallinger said.
Though the system is simple enough, the gas pumped out of it still needs to be treated, area manager Fred Eggleston said.
Moisture and other contaminants have to be removed from the gas, just as they would have to be if the reservoir were being tapped for the first time, Eggleston said.
Mercaptan, the sulfurous noxious substance that alerts the nostrils to the presence of methane, is injected into the delivery system at the Asbury wellhead, Eggleston said.
It’s not possible to use the Asbury and Fruita fields alone to supply the Grand Valley, Eggleston said, “but it sure can help with supply.”