Modelling fluid flow in complex 3D fault networks

Faults play a critical role in controlling the movement of mineralising fluids and the resulting formation of mineral deposits. Numerical models are useful for understanding fluid pathways through faults and their host rocks. However, the heterogeneous and multi-scale nature of fault zones can make numerical modelling a challenge, and studies applied to specific locations tend to be expensive as they require custom-built models of complex 3D geometries. Here, we present a series of tools to investigate fluid flow in fault zones at various length-scales. We introduce tools to automate rapid building of 3D meshes, on which Finite Element simulations can be run efficiently. The fault core and surrounding damage zones can be modelled as flat or volumetric features, depending on their scale and permeability characteristics. We highlight the impact of these fault components on fluid flow localisation, and consider specifically three aspects of fault networks: a map of intersecting fault traces, the effect of varying dip of non-planar faults, and the impact of intersecting damage zones. The numerical tools enable rapid investigation of scenarios involving complex fault networks as commonly observed in sedimentary basins.