Simulating enhanced production in fractured formations using dual porosity model with a simplified finite element algorithm

Abstract

Simulating the production process in natural fractured formations can be performed by the well-known dual-porosity model. Factors related to geomechanics can be crucial for production as both the deformation of the formation and the locally induced stresses can contribute to the pressure changes significantly, particularly in low-permeability and tight formations. A fully coupled, dual-porosity reservoir geomechanics model is developed and presented in this article, focusing on the computational efficiency, without however sacrificing accuracy. In the proposed model, displacements, the saturation and the two system pressures (matrix/fracture) are considered the primary variables and the system is solved in an iterative manner, following a fully coupled approach for the displacements and one of the system pressures, so that the overall problem dimensions to be reduced from four to two. Calculated stresses, pressures and production rates are analyzed and implications to hydraulic fracturing and stimulated reservoir volume (SRV) calculations are discussed and addressed.