Optimization of key cavity construction parameters of Jintan salt-cavern gas storage

During the engineering construction of Jintan Salt-Cavern Gas Storage, the lack of cavern construction experience leads to the decrease of cavern construction speed and effective cavern volume and seriously restricts the storage construction speed. In order to increase effective cavern volume and cavern construction speed, this paper analyzed the on-site cavern construction data and optimized the key cavern construction technologies as follows. The circulation mode of water injection is primarily reverse and secondarily direct. When a sump is constructed for the first time, the diesel blanket is generally 30-40 m away from the inner tubing inlet. The lift height of the diesel blanket is about 15 m in the stage of main construction and not more than 10 m in the stage of roof forming. The water injection rate increases step by step and remains stable and constant. The average water injection rate is 80-90 m³/h in the stage of sump construction and 90-100 m³/h in the stage of main construction. The optimized inner-outer tubing inlet distance during direct and reverse circulation of main construction is not smaller than 45 m and 10 m, respectively, which can effectively ensure the brine mass concentration. The research results provide the reference for the optimization of construction parameters of salt-cavern gas storage.