Multiphysics and multiscale modeling of fluid-injection-induced geomechanical implications: A review

Geomechanical issues like surface uplift and induced seismicity resulting from large-volume fluid injections into subsurface formations are critical challenges in subsurface engineering projects. These issues arise from complex multiphysics coupling and multiscale features that significantly affect the mechanical properties and integrity of rock formations. Understanding rock behavior under coupled thermo-hydro-mechanical-chemical (THMC) processes is crucial for the safe and efficient development of underground resources and space. This paper provides a comprehensive review of THMC coupling effects, multiscale phenomena, and numerical simulation methods in underground energy engineering. Five key and typical engineering applications, including geological carbon sequestration, enhanced geothermal systems, waste fluid injection, aquifer geothermal battery energy storage, and aquifer hydrogen storage, are examined to illustrate the progress and challenges in applying THMC coupling and multiscale analysis. The review highlights limitations in current approaches regarding mechanical constitutive models, failure analysis, fracture initiation and propagation, geochemical damage mechanisms, and the integration of physics-informed neural networks. Future research aimed at overcoming these limitations to advance the field is also outlined.