Encryption method and device for densification well in carbonate reservoir water-gas alternating drive development

The invention discloses a densification method and device for a carbonatite reservoir water-gas alternating drive development densification well. The method comprises the following steps: constructing an oil reservoir numerical simulation model according to a preset oil reservoir geologic model of a target block and obtained production dynamic data of the target block; according to the reservoir numerical simulation model, simulating gas-water alternating drive development, and determining a remaining oil enrichment area of the target block; according to the oil layer thickness and the oil layer area of each remaining oil enrichment area, screening to obtain at least one encryption potential area; determining a plurality of encryption well positions in at least one encryption potential area, and obtaining an encryption priority of each encryption well; and according to the encryption priority of each encryption well, the maximum single-day oil production of the FPSO and the simulated single-day oil production