Modeling proppant transport and settling in a 3D propagating fracture

Abstract Hydraulic stimulation is essential for creating hydraulically conductive fractures for geo‐resource extraction, including hydrocarbons, geothermal energy, and minerals. The effectiveness of this process is closely linked to the fracturing scheme employed and the deposition and accumulation of proppant particles within the stimulated fracture void space. The fracture propagation is strongly influenced by the geomechanical characteristics of the host rock, while proppant transport and settling are primarily governed by the rheology of the slurry mixture. The final geometry of the fracture, determined by the aperture distribution after shut‐in and fluid pressure release, is crucial for maintaining fracture conductivity. This study introduces a novel computational tool for the coupled numerical simulation of hydraulic fracturing and the circulation of proppant‐fluid mixtures within a fractured host rock. The application used the multiphysics object‐oriented simulation environment (MOOSE) PorousFlow module and extended it with equations governing the circulation of proppant‐laden slurries, including particle‐driven processes such as gravitational settling and concentration‐dependent density and viscosity. The mechanical processes in the propagating fracture are implemented using the MOOSE‐based Discontinuous Galerkin (DG) kernels and a cohesive‐zone law on the fracture interface. The coupling of both physical processes is achieved by exchanging critical properties, including slurry density, viscosity, fluid pressure, and local fracture aperture. The implemented hydraulic‐fracturing and proppant‐transport modeling capabilities were validated by benchmarking against analytical solutions and experimental results, respectively. Coupled simulations show promising outcomes in modeling the simultaneous injection of proppant during continuous hydraulic fracturing. This high‐fidelity computational tool lays the foundation for optimizing subsurface stimulation of resource recovery.