Predicating method for stratum pressure of water injection and polymer injection well area

The invention relates to a predicating method for stratum pressure of a water injection and polymer injection well area, and belongs to the field of oil-gas field exploration and development. The predicating method comprises the following steps of dividing a target layer of a point to be drilled into a plurality of single layers, splitting single-layer injection amount and production amount, and utilizing a material balance method to calculate single-layer average pressure; calculating pressure at corresponding pressure predicating depth of the point to be drilled according to the yield, pressure data and well spacing of a well around the point to be drilled; and enabling the pressure predicating depth of the point to be drilled to correspond to the certain single layer, and calculating apressure value, on other single layers, of the point to be drilled according to a geometric relationship between the pressure of the pressure predicating depth of the point to be drilled and the corresponding single-layer ave