(Photo provided by Dominion Energy Transmission Inc.) The Lightburn Station in Lewis County is Dominion Energy Transmission Inc.’s largest compressor station in West Virginia. A compressor injects and withdraws natural gas from underground storage pools.

PARKERSBURG — Although spring has allegedly sprung and temperatures are expected to start rising and staying warmer, this is the time of year natural gas suppliers start preparing for the winter heating season.

“Typically, we use the period from April 1 to Oct. 31 to inject the natural gas into our storage fields,” said John Love, director of gas storage and land services for Dominion Energy Transmission Inc. Suppliers “pay us, basically, to store the gas over the non-winter months so we’re filled up and ready to go” for winter.

About 50 percent of the natural gas DETI transports during the winter comes from underground storage facilities, said Frank Mack, communications project manager for the company. The rest comes from production fields such as the Marcellus and Utica shale formations, conventional wells and the Gulf of Mexico.

Storing the gas allows customers — including local distribution companies like Dominion Energy West Virginia, industrial facilities, power generators and marketers — to purchase it when demand is lower. That leads to lower prices for consumers, Mack said.

“Dominion Energy West Virginia will buy the gas during the summer, when it’s less expensive,” he said. “We store it for them and we transport it, but they own it.”

(Photo provided by Dominion Energy Transmission Inc.) Oriskany sandstone is one example of the type of formation in which natural gas is stored underground by Dominion Energy Transmission. This sample was extracted from a storage formation about 5,000 feet below the surface at the Ellisburg storage pool in Potter County, Pa.

Dominion Energy West Virginia is a distribution company that serves nearly 44,000 customers in Wood and surrounding counties, more than 32,000 of them in Parkersburg, Mack said.

According to information provided by the West Virginia Department of Environmental Protection, there are 31 underground natural gas storage fields in West Virginia, all but one of them in depleted natural gas reservoirs. Natural confining mechanisms in the geological formations keep the gas inside until the companies need to withdraw it, according to information provided by DETI.

DETI has three natural gas storage fields in West Virginia. The biggest — and one of the largest in the country — is Kennedy-Lost Creek, located predominantly in Lewis and Harrison counties, although a portion is beneath Doddridge County as well, Mack said. It has a total capacity of more than 167 million cubic feet, according to data provided by the West Virginia Department of Environmental Protection.

The Racket-Newberne field is beneath portions of Ritchie and Gilmer counties.

Columbia Gas Transmission has fields below Jackson and Wirt counties, while Equitrans has storage fields under Doddridge and Wetzel counties.

Depleted reservoirs are reworked when they are converted to storage spaces, Love said. In most, new casing is run into the well and cement is used to seal space between other casings and the drilled hole to prevent gas flow through those areas, Mack said.

The company utilizes periodic inspections to monitor the integrity of the wells through which gas is injected into the storage fields. The facilities are also inspected by regulatory agencies such as the DEP.

DETI has a total of 17 natural gas storage pools in West Virginia, Pennsylvania and New York, containing 756 billion cubic feet of natural gas. About 55 percent of that is injected and withdrawn for customers and storage partners, while the remainder is stored as a base gas to provide the necessary pressure support, according to information from the company.

These natural gas storage fields are different than the proposed Appalachian Storage Hub, which would keep natural gas liquids underground and is predicted to lead to billions of dollars in development and thousands of jobs. Natural gas liquids are materials like ethane, propane, butane and pentane separated from the gas and used in a variety of applications.