MountainWest Overthrust Pipeline LLC (Overthrust) is seeking US Federal Energy Regulatory Commission (FERC) authorization to expand its interstate natural gas transmission system by constructing, installing, modifying, operating, and maintaining its Westbound Compression Expansion project. The purpose of the project is to enable Overthrust to provide an additional 325,000 dekatherms per day of firm natural gas transportation service from two existing interconnects to a new delivery point near Overthrust’s existing Roberson Compressor Station beginning with the 2025/2026 winter heating season. The proposed project increases capacity to Opal, a major regional natural gas hub in Wyoming, allowing for additional gas production to meet growing regional and West Coast demand.
Overthrust plans to construct, install, modify, operate, and maintain two new compressor packages, adding approximately 31,800 hp (23,723 kW) to its operations. One of the two new compressor packages will be located at Overthrust’s existing Point of Rocks Compressor Station, and the other will be at the existing Rock Springs Compressor Station, both located in Sweetwater County, Wyoming.
At the Point of Rocks Compressor Station, one new Solar Mars 100-16000S compressor package will be installed, consisting of a Solar Mars turbine engine driving a Solar C452 centrifugal compressor. The new compressor package will provide an additional 15,900 hp (11,861 kW), bringing the total horsepower at the station to 31,900 hp (23,797 kW). Further facilities include a tie-in valve assembly, discharge gas cooler, fuel gas lines, and other ancillary equipment.
Overthrust also proposes to install and operate an additional compressor package at the Rock Springs Compressor Station that is identical to the Solar Mars 100-16000S compressor package at the Point of Rocks Compressor Station. With the additional 15,900 hp from the package, total horsepower at Rock Springs will increase to 46,900 hp (34,987 kW). Further facilities include a tie-in valve assembly, discharge gas cooler, fuel gas lines, fuel gas heater, and other ancillary equipment.
