Process method for preventing dissolution by injecting nitrogen into immovable string of salt well group and application of process method

The invention belongs to the technical field of salt mine solution mining and cavity construction solution resistance, and particularly relates to a process method for salt well group immovable string nitrogen injection solution resistance. Comprising the following steps: selecting a movable skid-mounted or split module to generate nitrogen and inject nitrogen; single-shaft gas injection is carried out from a production casing by adopting a mode of injecting local shaft volume nitrogen, and the gas injection amount is determined by the salt well daily exploitation amount and the compression coefficient of the located gas; and after gas injection is completed, anti-slip rear displacement liquid is injected to delay gas floating, and then well entering liquid such as clear water or brine is injected to rapidly displace gas in the production casing into the dissolving cavity and play a top dissolution resisting role. According to the method, the salt well gas injection process can be simplified, operation links