A fully coupled numerical model of thermo-hydro-mechanical processes and fracture contact mechanics in porous media

A range of phenomena in the subsurface is characterised by interplay between coupled thermal, hydraulic and mechanical processes deforming structures such as fractures. Modelling dynamics can provide valuable phenomenological understanding, but requires models which faithfully represent involved; these models, therefore are themselves highly complex. This paper presents a mixed-dimensional thermo-hydro-mechanical model designed to capture process-structure using discrete-fracture-matrix framework. It incorporates tightly based on laws for momentum, mass entropy subdomains representing matrix lower-dimensional fractures fracture intersections. The deformation explicitly represented modelled contact mechanics relations Coulomb friction law, with particular attention coupling dilation governing equations both matrix. discretised multi-point finite volumes balance semismooth Newton scheme conditions implemented open source simulation toolbox PorePy. Finally, studies demonstrate model's convergence, investigate effects, explore different show an application 3d geothermal pressure stimulation long-term cooling scenario.