Modeling Of Normal Net Stress Effect On Fracture Relative Permeability And Its Effect On Oil Recovery From Fractured Car

Abstract

Summary In this work, we investigate the effect of alteration of fracture total permeability, relative permeability and capillary pressure with the change of normal net stress (due to fluid injection or depletion), on estimated oil recovery factor from fractured carbonate reservoir. The numerical experiments are performed in two steps: first, we predict two-phase fluid-flow properties of fracture for different levels of normal effective stress using our in-house geomechanical model; and second, we study the effect of normal net stress in the reservoir on oil recovery factor, using conceptual simulation models and a commercial simulator. Our main conclusions of this study: Oil recovery and water production in fractured carbonate reservoirs is controlled by, not only the fracture permeability (and other matrix related parameters), but also fracture rock curves. Complex behavior of fluid flow in fractures cannot be captured only by varying fracture permeability. Shape of relative permeability and its dependence on the effective stress have a significant impact on flow of water vs. oil.