Advances in multistage fracturing combined with horizontal drilling have made this technique the driving force for the recent spectacular success in shale gas development and production. In this paper, a hierarchical approach integrating discrete fracture networks with multi-continuum concept is proposed to model various coupling mechanisms of gas nonlinear transport in shale. The hybrid model is composed of three continuum layers: organic matter, inorganic matter and micro-fractures in matrix which are treated as a continuum medium, and the discrete fractures are embedded into the micro-fracture-continuum. The extended finite element method is employed to decouple the mesh conformity between the mesh of media and the discrete fractures. The results of long-term well-performance dynamics are used to show the power and flexibility for simulating the multi-continuum/discrete-fracture interactions during gas transport in shale. The effects of fracture geometry and coupling flow mechanisms on gas production are also analyzed in this paper.

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