Research On Cycle Water Injection Method Of The First Infill Well Pattern In The Middle Block Of Southern Third Region

Cycle water injection technology is by periodically changing the injection and produced volume and creating unstable pressure field in the strata to make the fluid in oil layers continuously be redistributed, so that resulting additional cross flow of oil and water under the action of interlayer pressure difference and capillary imbibition, increasing water swept volume and improving water flooding effectiveness. This technology is one of the major methods of potential trapping in thick oil layers of water flooding blocks at the late period of high water cut stage during oilfield development.This cycle water injection technology is used in infill well pattern of low permeability layer in this paper. On the basis of precise remaining oil analysis and according to the characteristic of reservoir exploitation of infill well pattern, layer section method of cycle water injection of infill well pattern is optimized by taking interactive stopping-injection cycle method in upper and lower segment of the whole well, and the cycle water injection intensity and water injection cycle suitable for the first infill well pattern is researched combining with numerical simulation technology; The feasibility of cycle water injection of the first infill well pattern is evaluated comprehensively by testing and studying the features of cycle water injection of the first infill well pattern. After the implementation, the rates of production decline water cut increase are both controlled effectively and reservoir producing situation is improved, so that we can further reduce the inefficient cycle water injection, tap the remaining oil in oil layers and improve the development effect of the first infill well pattern at late high water cut stage. The research results of this project have an important guiding significance for the full implementation of cycle water injection of the first infill well pattern in Sanan development area.