A particle-tracking formulation of advective–diffusive heat transport in deformable fracture networks

Modeling heat transfer in complex heterogeneous fractured system is key for geothermal energy applications. Discrete fracture network (DFN) modeling the classical framework to reproduce advective part of transport, which determined by connectivity and heterogeneity. This approach general sacrifices representation rock matrix, disregarding both its diffusive exchange with fractures effects thermo-mechanical deformation on aperture. Here we propose a new semi-analytic formulation that can be implemented DFN simulator particle tracking approach. The contribution matrix terms thermal contraction/expansion analytically evaluated, respectively impact aperture variation. method proved accurate robust. Results from simulations cold fluid injection show contraction affects transmissivity, accelerates transport resulting faster recovery at outlet. methodology enables investigating reservoir behavior optimizing performance while keeping computational effort within reasonable values. allows exploring uncertainty cases when situ characterization poor, spirit modeling.