Objective Against the backdrop of "dual carbon" goals and energy security demands, deep underground energy storage is a crucial approach for large-scale energy storage. Numerical simulation studies are vital for optimizing the design and operation of these systems. This paper focuses on the progress of numerical simulations for major geological storage media (salt caverns, rock caverns, and porous media), and analyzes the key scientific issues and technical challenges in different storage scenarios.

Method By systematically reviewing domestic and international literature, this paper summarized the numerical simulation methods and findings for hydrogen storage, natural gas storage, and compressed air energy storage from the perspectives of geological characteristics, multi-physics coupling models, and operational parameter sensitivity. Key attention was paid to the thermodynamic response of salt caverns, the structural stability of rock caverns, and the seepage characteristics and cushion gas effects in porous media.

Result The review shows that: for salt cavern storage, thermo-hydro-mechanical (THM) coupled models offer improved accuracy over conventional models; during the charge-discharge cycles in rock caverns, thermal and density stratification, as well as humidity variations, are observed; in porous media, the type of cushion gas and the characteristics of the geological formation significantly affect storage performance.

Conclusion Numerical simulations for deep underground energy storage require strengthening research on multi-physics coupling mechanisms, damage evolution of geological media, and long-term cyclic reliability. This will provide theoretical support for the engineering application of geological formations such as depleted oil and gas reservoirs. Future research should focus on the coupling of multiple conditions, leakage prevention and control, and the synergistic utilization of geothermal energy.