Underground salt caverns have been widely used for oil and gas storage and have attracted increasing attention. The construction design of salt caverns is directly related to the final storage capacity, economic benefits, and resource utilization. However, due to the numerous combinations of multi-stage process parameters involved in the construction design, it is difficult to optimize them individually through indoor experiments and numerical simulations. In this regard, this paper attempts to put forward the basic principles of cavern construction design criteria with economic benefits and resource utilization as indicators. Firstly, 1258 groups of cavern construction process parameters were randomly generated under certain basic rules, including inner tube depth, outer tube depth, oil pad depth, duration, and water injection flow rate, for five direct leaching stages. Then, the cavern capacity, economic benefit, and rock salt resource utilization corresponding to these process parameters were obtained through batch processing using single-well salt cavern leaching simulation software (SSCLS). Finally, the influence laws of the distance between the inner tube and oil pad and lifting heights, and the rates of the inner tube and oil pad on the expected economic benefits and salt resource utilization, are discussed. In the actual project, it is recommended to increase the distance between the inner tube and the oil pad, increase the ratio of oil pad lifting height to duration, and use the appropriate lifting height to obtain greater expected revenue and resource utilization. This work will improve the efficiency and scientificity of cavern construction design, which is of great significance in guiding the construction and design for energy storage in salt caverns.

With the rapid development of clean energy in China, the demand for underground energy storage is increasing. This paper reviews the current status of underground energy storage and advances in safety assessment and environmental-impact mitigation. Depleted oil and gas reservoirs and salt caverns are the primary geological formations for natural-gas and compressed-air energy storage in China. As of October 2024, eight salt-cavern and 26 depleted-reservoir facilities had been constructed, accounting for approximately 90% of large-scale underground storage facilities. Oil and natural gas are the most mature storage media, followed by compressed air and carbon dioxide (CO₂), whereas underground hydrogen and helium storage remain at earlier stages of development. The review compares salt caverns, depleted reservoirs, aquifers, and rock caverns in terms of capacity, sealing, cost, cycling capability, and risk. It further synthesizes theoretical, numerical, experimental, and monitoring studies. The principal risks include well or fracture leakage, caprock or cavern sealing loss, pressure-induced fracturing, salt creep, cyclic damage, hydrogen-related microbial and geochemical reactions, material degradation, and CO₂ plume migration. Long-term monitoring should combine pressure, temperature, flow rate, gas composition, well integrity, deformation, microseismicity, groundwater chemistry, surface-gas geochemistry, and plume imaging. Future development should advance abandoned-mine pumped-storage hydropower, CO₂ geological storage, and underground hydrogen storage through field-scale validation, coupled multi-physics models, hydrogen-compatible materials, and unified integrity standards.