Modeling Fully Coupled Oil–Gas Flow in a Dual-Porosity Medium

Abstract

A finite element model has been developed to simulate two-phase, (i.e., oil and gas) flow and solid deformation in a dual-porosity medium. The model accounts for coupling between solid deformations and fluid flow in both the primary medium (representing the matrix pores and solid) and the secondary medium (used to represent fractures in the present study). The model is verified against relevant analytical solutions and then applied to the problem of an inclined wellbore under generalized plane strain conditions, subjected to a three-dimensional in situ state of stress in a fractured formation saturated with oil and gas. A parametric study has been carried out to demonstrate the effect of dual-porosity parameters, phase saturations, and interaction between the two media. The implementation of double effective stress laws in the present study is a significant deviation from some classical dual-porosity models and helps to incorporate the effect of deformation of the secondary medium (representing the fractures).