Low-permeability reservoir CO2 miscible-phase displacement front prediction method based on flowing bottomhole pressure

The invention discloses a low-permeability reservoir CO2 miscible-phase displacement front prediction method based on flowing bottomhole pressure. Comprising the following steps: S1, constructing an oil reservoir numerical simulation model; s2, characteristic parameters of the target oil reservoir are counted, and the flowing bottomhole pressure, the dynamic change of the front edge position and the CO2 breakthrough time under different conditions are obtained; s3, establishing a relational expression between the dimensionless leading edge position and the bottomhole flowing pressure derivative; s4, determining the influence of each factor on the CO2 breakthrough time by adopting a grey correlation method, and correcting an influence factor set; s5, adopting a multiple linear regression model to obtain a prediction model of the fitting parameter miscible front under multiple factors; and S6, on the basis of the basic parameters of the oil reservoir, obtaining a miscible-phase front prediction model with diffe