A generic workflow of projection-based embedded discrete fracture model for flow simulation in porous media

Numerical modeling of multiphase flow phenomena in fractured porous media has always been a hot topic in recent years. Projection-based embedded discrete fracture model (pEDFM) is a recently developed modeling framework that has been shown to resolve some limitations of the commonly used embedded discrete fracture model (EDFM). However, determining the continuous projection path of fracture networks and adding needed fracture-fracture (f-f) connections in the previous pEDFM workflows is too complicated to construct a generic and easy-to-program algorithm. Although there are several studies about applications of pEDFM to numerically model the flow problems in fractured porous media, a generic pEDFM workflow has not been truly formed. Therefore, this theoretically advanced numerical modeling framework of flow problems in fractured porous media has not been widely noticed and applied. To construct a generic pEDFM workflow, this paper first illustrates that the fracture projection path obtained by the micro-translation method can achieve acceptable simulation accuracy for flow across a high-conductivity fracture, then a generic and easy-to-program non-projective method is developed to model low-conductivity fractures. Numerical examples verify that the developed pEDFM workflow can effectively handle low-conductivity fractures (e.g. flow barriers) in general cases, thus avoiding the difficulty of developing a generic algorithm for constructing a continuous projection path for the low-conductivity fracture. It is also verified that the new pEDFM workflow with the addition of simple f-f connections can solve the cases that classical pEDFM solves with significant errors. Furthermore, it achieves similar or better computational accuracy than the pEDFM modified by adding complex f-f connections, thus avoiding the difficulty of developing a generic algorithm for constructing these additional f-f connections. Overall, the first generic pEDFM workflow is developed in this paper, which significantly improves the practicability of pEDFM and may induce more applications of pEDFM in numerical modeling of flow problems in fractured porous media.