Because the contradiction among layers cause drilling infill well damage the oil layer in the Sazhong area and cause casing to be damaged, it is proposed that injection well shut-in depressurization adjustment technology controls the pore pressure of the layer, achieve the purpose of protecting the casing and the oil layer, moreover, the interlayer pressure difference is reduced, and the well cementation quality of new drilling accordingly is improved. In this paper, the field test of the injection well shut-in depressurization adjustment technology and the application of this technology in the drilling process are studied. The research shows that this technology can be directly applied to the subsequent encryption adjustment wells and the drilling production in the polymer flooding, it is of great significance for reducing the oil layer pollution, protecting the casing and improving the quality of the drilling engineering for subsequent drilling.