To deepen the understanding in impacts of heterogeneous and anisotropic fracture roughness on thermal breakthrough in geothermal doublet systems, a thermo-hydro-mechanical model incorporating spatially-autocorrelated random field is introduced. Using the coupled numerical model, this work addresses the research gap of field-scale study for anisotropy of heat transfer, flow and deformation in fractures, and further investigates the influence of well layout on thermal performance, which gives insights into the configuration of enhanced doublet systems for the development of geothermal reservoirs.