Numerical Investigation on Dispersive Characteristics of Fracture Networks

Abstract:

Geometrical configuration of fracture networks and the network connectivity impart dispersion to migrating plumes of particles. Plumes are often observed to grow in asymmetric patterns facilitated by highly conductive pathways. The observed variance is profound even in cases with negligible molecular diffusion (either longitudinally along the fracture segments or between the fractures and rock matrix). A DFN framework with steady-state flow fields are used to track particles through two-dimensional stochastic fracture networks with realistic statistical attributes. Separation statistics between particle pairs are utilized to characterize plume growth and scaling behavior under different transport regimes. These transport regimes, in turn, are then linked to quantitative properties of the fracture network, mainly distributions of fracture length and transmissivity.