Financial terms of the deal weren't disclosed.
Calgary-headquartered Encana has been reducing its portfolio and recently agreed to sell natural gas properties in Wyoming to a private equity firm.
Denver-based Encana Natural Gas Inc. distributes liquefied natural gas (LNG) fuel to operators of high horsepower engines used in the oilfield, mining, rail, marine, over-the-road transportation and industrial sectors.
Stabilish will add ENGI's staff and buy its fleet of trailers, mobile fuelling units and other equipment.
The transaction is scheduled to close on April 30.