Low-grade geothermal potential of the Regina - Moose Jaw area, Saskatchewan

CIM Bulletin, Vol. 72, No. 810, 1979

L W. VIGRASS, D. M. KENT and R. J. LEIBEL, University of Regina,, Regina, Saskatchewan

Porous and permeable rocks deeply buried in sedimentary basins contain immense volumes of hot water with the potential to supply low-grade heat energy. A part of Canada with sizeable potential for low-grade geothermal energy is the northern Williston Basin of southern Saskatchewan. In this region, the University of Regina has conducted a geological study investigating the feasibility of producing large quantities of warm water suitable for space heating in the Regina - Moose Jaw area. The study has shown that the most favourable geothermal reservoirs are in the Basal Clastic Unit (Cambrian-Ordovician), which, at an approximate depth of 2,000 metres, has predicted temperatures of 71°C to 74 °C. We anticipate sustainable flow rates from these reservoirs of 100 to 300 m3/hr. The water contains about 150,000 ppm of total dissolved solids, mostly sodium chloride. It is anticipated that the sulphate content will be 3,000 to 6,000ppm, that the dissolved oxygen and hydrogen sulphide content will be small, and that the waters will be neutral to slightly alkaline. It is anticipated that the piezometric level will be 46 m below the ground surface for reservoirs in the upper part of the Basal Clastic Unit and 141 m below the ground surf ace for the lower reservoirs of the unit.Plans are to build a low-grade geothermal research, testing and demonstration facility at the University of Regina. To be a practical demonstration, the facility will have to handle very large volumes of water. Because of high salinity, the water will be reinjected into a subsurface reservoir. We do not anticipate insurmountable problems because of salinities or as a result of corrosion provided that the waters are not aerated during handling.
Keywords: Energy resources, Geothermal energy, Regina area, Moose Jaw area, Williston Basin, Stratigraphy, Water flows, Temperature measurements, Salinity, Piezometric levels, Seismic data.