Numerical simulations of flow and transport in three-dimensional fractured formations

Abstract:

The fractures and pores in rocks are the fundamental units for calculations of flow and contaminant transport in fractured formations. Modeling and meshing of a fractured rock system are challenging tasks because mesh generations of fractured networks typically involve complex procedures for topological transformations and the modeling of such complex mesh system is computationally expensive. Due to technical and logical limitations it is difficult in reality to account for such small units for simulations of flow and transport in large-scale problems. The concept of continuum representation of fractured rocks can provide an alternative to resolve the limitations of highly computational costs for flow and transport simulations. For these types of approaches the evaluation of representative parameter such as the equivalent permeability for a fractured rock is critical for accurate predictions of flow and transport in large-scale fractured formations. This study aims to develop a three-dimensional discrete fracture network (DFN) model, an unstructured mesh generation system, and a finite element flow and transport model for fractured rock systems. The behavior of equivalent continuum permeability based on different fracture properties were then systematically discussed. Results of this study are expected to provide general insight into the procedures and the associated techniques for analyzing flow and transport in complex fractured rock systems.