HELENA — NorthWestern Energy, the state’s biggest natural gas utility, says it will buy a large natural-gas production field in northern Montana, expanding ownership of the gas it supplies to Montana customers to 37 percent.
NorthWestern announced late Tuesday it has agreed to buy the field from Oklahoma-based Devon Energy Production Co., as well as acquire Devon’s interest in a gas pipeline that runs from north of Great Falls to the Canadian border.
NorthWestern spokeswoman Claudia Rapkoch said Wednesday the purchase is part of the company’s ongoing strategy of buying natural gas production assets that can lock in long-term supply at a stable price for its customers.
“One thing everyone learned over the last decade on gas prices, is that they became so volatile,” she said. “What we see this providing, as with all of our own assets, is stability going forward, to minimize any future price volatility.”
In the rush to “restructure” in the late 1990s, NorthWestern’s predecessor, Montana Power Co., sold its natural gas wells and began acquiring gas for its Montana customers entirely on the market. It had owned wells that provided about half the gas it needed for customers.
Starting in 2010, NorthWestern began looking to buy gas production fields to help supply its 183,000 Montana natural gas customers.
Rapkoch said the company is still exploring whether to buy more gas-production assets, in part because gas prices are well below their highs of mid-2008.
The price paid for the 916 wells and connecting pipelines owned by Devon should lock in a price for the field’s gas at around $4.10 per dekatherm for the next 20 years, the company said.
That price is about the same as the current market price for natural gas, which peaked at almost $11 per dekatherm in mid-2008, dropped to less than half that amount during the onset of the Great Recession and continued to fall to a low of less than $2 per dekatherm in early 2012.
Prices have climbed slowly but steadily since then, edging above $4 per dekatherm this spring.
Right now, NorthWestern customers are paying about $4 per dekatherm for their gas, plus the delivery costs, which are an additional $3.75 per dekatherm. The average household in Montana consumes about 120 dekatherms a year.
The company said the Devon gas field will produce 5.6 billion cubic feet of gas this year and has proven reserves of an additional 65 billion cubic feet. Overall, the company needs about 20 billion cubic feet a year to supply its customers.
When the new field’s gas is added to gas-production assets NorthWestern bought in 2010 and 2012, the company will own production for about 37 percent of the gas it delivers to customers, rather than buying it on the market. NorthWestern buys the remainder of gas needed for customers from producers primarily in Montana, Wyoming and Canada.
The Devon wells are in the Bear Paw Basin, northeast of Great Falls.
Rapkoch said NorthWestern doesn’t need regulatory approval to buy the wells, but the state Public Service Commission must approve whether to put them into the company’s rate base, allowing NorthWestern to earn a rate of return on its purchase price. That application will be made after the sale closes, she said.
Devon also employs about 50 people in Montana to operate its wells and pipelines. Rapkoch said NorthWestern will be meeting with Devon workers as it decides how many it may hire.