A research team from institutions including Chongqing University in China recently published a study on compressed air energy storage in low-grade inclined salt layers.

The research team conducted simulation analyses based on a simplified model of a salt cavern gas storage facility in Qianjiang City, Hubei Province, China. The researchers established different combinations of salt layer burial depth and formation dip angle, simulating the geological stability of the compressed air energy storage system under daily charge-discharge cycles over a 30-year operational period. The study selected volume shrinkage rate, plastic zone volume, maximum surrounding rock displacement, and safety factor as key evaluation indicators.

The results indicate that the shrinkage and displacement of the salt cavern intensify with increasing depth. The researchers found: "An increase in the formation dip angle exacerbates the asymmetry of the volume shrinkage rate and displacement in the lower part of the salt cavern." Simultaneously, interlayers within the salt layer have a buffering effect on surrounding rock deformation. Based on the simulation results, the research team suggests that for deep salt cavern gas storage facilities buried deeper than 1500 meters, the formation dip angle should be controlled within 20 degrees; for shallow salt caverns, the allowable dip angle can be appropriately relaxed.

The related findings have been published in the academic journal "Earth Energy Science."