A Model for Conductive Faults in Heterogeneous Media for Non-matching Grids

In the standard Corner Point Grid approach, a fault zone is supposed to be sufficiently thin to be represented as a surface with non-matching interfaces, due to the throw, across the fault. Following this point of view, we study an approach where fluid flow along the fault is modelized by a lower dimensionnal model, the fault thickness becoming a model parameter.A fault zone is represented by two sets of faces, corresponding to the fault surface, each set being conforme with its neighbouring matrix grid-blocks. Fault zone properties are assigned to each face. Finite Volume Discretization of fluid flow equations leads to an additional mass balance equations in each fault face, with three types of fluxes. The first one represents mass exchange between fault faces along each set. The second one is between neighbouring non-conforme fault faces across the fault and finally, the last one, is between fault faces and their neighbouring matrix grid-blocs. In this paper, we mainly focus on how to handle the non-matching grids and therefore consider only one-phase fluid flow. However, the extension of this approach to complex multiphase flow is straightforward as it enters into the Finite Volume framework.