Hydromechanics Model of Natural Gas Transport in Stress-sensitive Dual-porosity Medium

Abstract

The assumption of constant permeability is not strictly applicable to porous media where rock properties undergo changes, such as stress-sensitive gas reservoirs. This study developed a hydromechanics model of a horizontal well in dual-porosity media considering the stress-sensitivity effect. The solution methods include variable substitution, perturbation technique, Laplace transformation, Sturm-Liouville eigenvalue theory, orthogonal transformation and numerical inversion. The results showed that the production rate decreases with the increasing of permeability modulus and the derivative curve will be warped up during the whole system late radial flow stage. The research has both theoretical and practical significance in predicting production performance and evaluating underground fluid transport in such formations.