Insights into Fracture Dynamics Through Advanced Coupled Flow and Geomechanics Modeling

ABSTRACT: This work develops an advanced coupled flow and geomechanics model, integrating the Embedded Discrete Fracture Model (EDFM) and the Extended Finite Element Method (XFEM), to enhance unconventional reservoir exploration. The model, now refined for multiple fracture scenarios, uniquely simulates multiphase compositional flow and matrix-fracture deformations, overcoming the limitations of simplified empirical models in capturing dynamic fracture behaviors during the reservoir injection-production process. Benchmarked against established standards like Sneddon and Elliot's problem, the model through an iterative coupling accurately predicts fracture property changes under various reservoir and operational conditions. Key findings underscore the influence of matrix permeability and rock stiffness on fracture apertures and reservoir pressure as well as stress fields throughout development cycles. The study demonstrates that reduced fracture angles relative to the flow path lead to elevated reservoir pressures and more uniform fracture property changes, while higher pressure differentials intensify stress around fractures, correlating positively with fracture aperture variations. This model contributes to a better understanding of well productivity optimization and effective reservoir management, particularly in addressing the challenges posed by the dynamic properties of multiple fractures during the reservoir injection-production process. 1. INTRODUCTION The application of hydraulic fracturing has transformed tight formations into viable resources for the oil and gas industry, presenting both opportunities and challenges in reservoir management and production optimization (Gaurav et al., 2012; Wang et al., 2020; Mehrabi et al., 2021; Pei and Xiong, 2023; Wang and Olson, 2023). Despite the initial high production rates, the rapid decline in output due to fracture closure and conductivity loss remains a critical concern (Yu and Sepehrnoori, 2014; Fan et al., 2017; Xu et al., 2019). Additionally, the slip and opening of fractures induced by fluid injection are common in reservoirs rich in fractures and faults (Zoback and Gorelick, 2012; Kumar and Ghassemi, 2018; Ren et al., 2018; Kamali and Ghassemi, 2020). Such changes, driven by variations in pore pressure and the consequent response in local in-situ stresses (Marongiu-Porcu et al., 2016; Safari et al., 2017; Pei and Sepehrnoori, 2022; Pei et al., 2022), necessitate a precise understanding of fracture dynamics to sustain reservoir productivity.