Numerical simulation of two-phase heat and mass transfer in fractured reservoirs based on projection-based embedded discrete fracture model (pEDFM)

Abstract

pEDFM is a newly developed numerical simulation framework for mass transfer in fractured reservoirs, and this paper aims to study the application of the pEDFM framework to numerical simulation of two-phase heat and mass transfer in fractured reservoirs. Firstly, the finite volume method is used to discretize the mass and energy conservative equations. Then, all the connections between control volumes including two types of fracture-matrix (f-m), three types of fracture-fracture (f-f) and one type of matrix-matrix (m-m) connections are constructed, and corresponding transmissibility formulas of mass and heat transfer in finite-volume discrete schemes for these connections are given, and Newton iteration method is used to solve the fully implicit coupled discrete equations to obtain cell temperature, pressure and water saturation. Finally, two numerical examples including multiphase flow across high-conductivity fractures and flow barriers are implemented to show that pEDFM can eliminate the errors in EDFM for the calculated temperature profiles. An application case that applies waterflooding to a fractured reservoir model with a fractured horizontal well, four water injection wells, natural fractures and a fault is considered to show that, compared with EDFM, pEDFM can more accurately and effectively handle the numerical simulation of mass and heat transfer in realistic fractured reservoirs with complex geological conditions.