Deep geothermal energy in Canadian sedimentary basins VS. Fossils based energy we try to replace – Exergy [KJ/KG] compared

Abstract

Low efficiency of turbines used in geothermal power production, along with large power demand for geothermal fluid pumping, limits use of geothermal resources for power production in the Canadian low to mid enthalpy basins. Much larger areas of Canadian sedimentary basins have potential for geothermal direct heating, but use will be dependent on the amortization period of the installation cost as well as the parasitic power demand to maintain large flow rates in injection and production wells. Maximum exergy (kJ/kg) potential for the most perspective geothermal resources in the deeper parts of Canadian basins (150 kJ/kg (0.15 MJ/kg)), are compared to exergy contained by the intrinsic chemical energy in oil, gas and coal (30–35 MJ/kg) that is required to be replaced in order to reduce carbon emissions. The calculated number of geothermal producing doublet well systems, at very high assumed flows of 0.08 m3/s (80 L/s), required to replace an average oil producing well in Alberta –WCSB will be > 10. But, such high exergy is available only in the deepest northern parts of the WCSB.