Heat resource potential and reservoir characteristics of fractured and dolomitized carbonates of the Beaver River gas field, Liard Basin, western Canada

Petroleum exploration and development in northern Canada revealed high-temperature resources with sustainable water flow rates in several dolomite-hosted gas reservoirs in the Manetoe facies, along the western margin of the Liard Basin that extends across NE British Columbia, SW Northwest Territories, and SE Yukon. This study examines the characteristics of fractured Manetoe dolomite reservoirs and evaluates the geothermal potential of the Beaver River gas field. The goal is to assess its viability for geothermal energy utilization to benefit northern communities. A volumetric method, coupled with a wellhead flow rate approach, was applied to estimate both heat resource potential and production capacity. In addition, a sensitivity analysis was conducted to identify key factors influencing heat production capacity. Our assessment indicates that the Beaver River gas field contains a recoverable heat energy resource of 1.9 × 10¹¹ MJ, with potential to generate more than 24 MW electricity for over 30 years. A single well in the field is estimated to have nearly 3 MW of gross electricity capacity. The sensitivity analysis identified flow rate as the most important factor for production capacity, highlighting the critical role of open fractures associated with faulting and folding from the Laramide Orogeny in enhancing reservoir permeability and deep-water circulation connecting to the Manetoe dolomite reservoir. A combination of hydrothermal dolomitization and post-diagenetic tectonic deformation makes the fractured Manetoe facies a unique reservoir/aquifer suitable for hosting both petroleum and geothermal resources. Furthermore, several large gas fields in the fractured Manetoe dolomite reservoir, along the same tectonic trend in the Liard Fold and Thrust Belt, share similar reservoir characteristics and production behavior, and may also contain substantial extractable geothermal resources. The detailed subsurface geology and production behaviors from those depleted natural gas fields can serve as analogs for geothermal exploration and wellsite selection in northern Canadian communities where reservoirs are not well characterized, such as the hamlet of Fort Liard, NWT. This study also provides valuable insights more generally for geothermal exploration within carbonate aquifers in deformed foreland basins.

Highlights

• Large geothermal potential in Manetoe facies carbonates of the Liard Fold and Thrust Belt

• Reservoir characterized by dual porosity-permeability, high flow rate, and slow pressure decline

• Beaver River gas field is a good analog for carbonate geothermal aquifers in deformation belt

• Alternative drilling site proposed for heat extraction in hamlet of Fort Liard