We suggest that fluid flow models can yield a proxy for structurally controlled mineralization in sedimentary basins. In these environments economic deposits form predominately where the upwelling fluids are localized by permeability contrast. Assessing the flow pattern therefore yields information that can be used to target specific regions within the basin.
Numerical fluid flow simulations in real-world geometries are always build upon simplifications and assumptions. Here we present recent improvements in handling permeability anisotropies and -contrast that arise in faulted and folded porous media. Commercial applications in which assessing the flow field or solute transport is critical include groundwater management, reservoir engineering, mine dewatering, in-situ recovery, and safe waste disposal.
In sedimentary basins large faults zones often act as feeders for the underlying mineral system. Localization of the upwelling fluids is controlled vertically by the fault zone architecture and horizontally by the bedding of the strata. A main challenge is the multi-scale nature of the problem with small scale features such as sedimentary partings and fractures governing the large-scale flow. To address this scale-separation, numerical homogenization can be applied converting the small-scale permeability variations into equivalent permeability tensors.
We propose that more reliable simulations can be obtained by meshing the geometric information obtained from in GIS (e.g., structural, and geological maps) and adding the superimposing fracture permeabilities that exist in fault damage zones and folded strata though homogenized values. The geometries of such fracture networks can be derived from structural mapping and from UAV’s. The anisotropy resulting from folding or dipping of sedimentary layers can be accounted for by rotating the permeability tensors based on potential fields that are derived from structural modelling (LOOP).
The resulting models represent a more realistic representation of the real-world geology and can inform exploration targeting in sedimentary basins.