Challenges and countermeasures in salt cavern underground storage in China—from “Jintan mode” to “XX mode”

The construction of salt cavern underground storages in China originated from the Jintan Salt Mine in Jiangsu province, achieving success and establishing the first technical standard system for salt cavern storage construction in China. However, the geological conditions of other salt mines in China differ significantly from those of the Jintan Salt Mine, such as NaCl grade, buried depth, salt rock thickness, and interlayer characteristics. Therefore, the construction of salt cavern storage faces numerous challenges, and the “Jintan mode” cannot be directly replicated. Focusing on the geological design of salt cavern storage, solution mining engineering, and gas injection and brine discharge schemes, this paper firstly summarizes the “European and American mode” of salt cavern storage construction and the basic characteristics of China’s “Jintan mode”, which basically developed from the “European and American mode”. Then, based on research and engineering practices in salt cavern storage construction of other salt mines in China, several typical “XX modes” are put forward, adhering to the principle of “one solution design for one region or one salt mine”. The “XX modes” differ from the “Jintan mode”, with great breakthroughs and changes. They represent technical solutions and new ideas to deal with the geological complexities of salt mines in China. Finally, the key theories and technologies that need to be researched further in the next step to cope with geology challenges of salt mines are prospected.