With geothermal gradients of up to 50°C/km, Alberta has the potential to use geothermal energy economically. Mathematical models are excellent tools to predict the flow of geothermal energy and to forecast the productivity of a geothermal reservoir.
This report investigates the flow of geothermal energy under the influence of water density variations due to temperature changes. As temperature increases, water density decreases, leading to upwelling of hot water. The associated interaction between heat flux and water flow is simulated numerically using an extended version of the HydroGeoSphere model that has been further developed.
Alberta Geological Survey developed a groundwater model that numerically simulates the coupled flow of formation fluids and geothermal energy. The model accounts for variations of fluid density and viscosity and for buoyancy-induced groundwater flow. A wide temperature range of 0°C to 300°C is covered. The model has been verified against existing numerical and analytical test cases of free convective geothermal groundwater flow. Future work will also incorporate the effect of water salinity on buoyancy-induced fluid flow.
Graf, T. (2009): Simulation of geothermal flow in deep sedimentary basins in Alberta; Energy Resources Conservation Board, ERCB/AGS Open File Report 2009-11, 17 p.