On the interaction between a geothermal borehole and groundwater flows

The presence of aquifers can highly affect the heat exchange between geothermal boreholes and the ground. To optimally design them, theoretical models for the thermal interaction of geothermal boreholes with groundwater flows are required. The present work exploits the presence of large disparities in time and length scales, using matched asymptotic expansion techniques, to build a mathematically rigorous and physically sound model that accounts for the presence of creeping groundwater flows. The derived model not only exhibits great performance compared to detailed numerical simulations but also serves to critically assess the merits and limits of the state of the art.