Layering is an Important Control in Fractured Reservoirs

Fractures are often bounded by layer interfaces. The usual explanation for this observation can be improved if we consider that fracture assemblies represent strain. Geomechanical simulations of deformations show that layer interfaces are often where strain gradients are high, or even discontinuous, due to both material-property contrasts, as well as interface properties. Using deformation simulation outcomes, it is possible to create models in which the fracture distributions are correctly linked to the necessary strain, providing a prior model against which stochastic methods can be conditioned. Such trap-deformation models lead to fracture predictions that are in good agreement with outcrop observations, providing a process explanation for the observed heterogeneities in terms of orientations, sizes and local intensities of fractures. Such distribution models make good inputs for the real-time understanding of fractured reservoir responses during production, where geomechanical interactions play a potentially strong role.