Fracture-vug type carbonate reservoir water breakthrough early warning method

A fracture-vug type carbonate reservoir water breakthrough early warning method of the present invention relates to an oil well water breakthrough early warning method, and aims to determine the water invasion time timely, optimize a working system, prolong an oil well water-free oil production period, and improve the oil well recovery efficiency. The method of the present invention comprises the following the steps of S01 obtaining the oil pressure drop under different accumulative liquid volumes according to a matter balance equation, and drawing a relational graph of the oil well pressure drop and the accumulative liquid volume; S02 for the non-water breakthrough reservoir, if a oil well pressure drop and accumulative liquid volume curve deviates, explaining three possible phenomena: (1) the crude oil is degassed in a shaft or stratum; (2) a new reservoir is exploited; (3) the edge-bottom water begins to invade; S03 excluding the two situations that the crude oil is degassed in the shaft or stratum and the