Estimating Pressure Losses in Interconnected Fracture Systems: Integrated Tensor Approach

Abstract

A significant number of petroleum reservoirs and almost all geothermal reservoirs are characterized by high in situ stress and fractures, and fractures act as major flow paths for fluids. An integrated tensor model is proposed to solve three tasks: characterization of a heterogeneous fracture network, simulation of fluid flow through a complex system for estimation of the grid-based permeability tensor, and unsteady-state fluid flow simulation for estimation of production and pressure losses. Deformation of the matrix and fractures are solved separately and used to compute their dynamic porosity and permeability. Finite-element methods and boundary element methods are used for numerical modeling. The results of this study show that the proposed model can overcome problems requiring excessive computational resources, flow interactions between the matrix and fracture, and the effect of matrix deformation on fluid flow. Results also show that the integrated tensor model serves as an efficient tool for predicting the effect of stress on fracture deformation and consequent productivity and/or injectivity of naturally fractured reservoirs.