Transport Upscaling under Flow Heterogeneity and Matrix-Diffusion in Three-Dimensional Discrete Fracture Networks

We investigate the combined effects of network scale flow variability and retention due to matrix-diffusion on scaling behavior transport through fractured media. Two principal mechanisms controlling solutes low-permeability media are broad distributions velocities times in solid matrix. study relative impact these two processes under different initial conditions using a set three-dimensional discrete fracture simulations. use simulations develop calibrate an upscaled continuous time random walk (CTRW) approach for advective based Ornstein-Uhlenbeck model particle that accounts fracture-matrix coupling compound Poisson process. This CTRW can be conditioned solute distribution allows observe late-time at distances beyond what is feasible high-fidelity direct numerical determine particles leads marked differences persistent long-term travel distributions, even those undergoing matrix diffusion implementation analysis model.