Advances in research on gas storage in sediment void of salt cavern in China

Salt cavern gas storage (SCGS) is a mature energy storage method that is applied around the world. Insoluble sediment particle (ISP) accumulated at the bottom of the salt cavern seriously affect the storage capacity of salt caverns. The ISP has greatly restricted large-scale underground energy in salt caverns in China. However, if the void in the ISP can be used for gas storage (SVGS), the gas storage capacity of salt caverns will be greatly improved. The sediment void is related to the grain size distribution, accumulation morphology, mechanical properties, and falling movement. Therefore, four models (grading model, accumulating model, mechanics and motion model, and simulation model) of the SVGS are constructed by the four theories (grading theory, accumulation theory, contact force chain and motion theories, and experiment and numerical theories) to analyze the feasibility of SVGS. Then, the practical application, model validation, and prospects of SVGS are also discussed. The models and practical application show that the SVGS is feasible, and it has wide application prospects. The research provides a favorable reference for the implementation of SVGS in China.