Research On Comprehensive Identification Method Of Thief Zone Between Injection And Production Wells In Water-drive Sandstone Reservoirs

The injection-production thief zone is the preferred water flow channel for water injection under certain geological conditions and well pattern conditions after long-term water flooding.After a long-term water flooding development in a certain block of Daqing Oilfield,most of the wells have entered a period of high water cut stage,and a large amount of injected water spearhead along the injection-production thief zone,resulting in inefficient or even inefficient circulation of water injected into many blocks,which greatly reduces the development effect of oil fields and economic benefits.This paper establishes a set of accurate,effective,and convenient identification method of injection-production thief zone to accurately identify the thief zone between injection-production interwell,and lays a foundation for targeted adjustment at the late stage of the oilfield.Through the fuzzy comprehensive evaluation,the optimized parameters are used as the evaluation index to establish the mathematical model of the injection and production orientation recognition.Using the "K-means" cluster analysis principle,the clustering analysis of the fuzzy comprehensive parameters obtained by calculation was carried out,and the recognition limit for obtaining the advantage of injection and production is 0.6.Based on the determination of the injection and production advantages,the limits of water saturation and oil displacement efficiency of the injection-production thief zone of reservoirs with different oil layers and different types of sand bodies are further studied.Ultimately,VC2010 will be used to compile relevant procedures to achieve programmed and standardization of recognition of injection-production thief zone,so as to ensure accurate and efficient completion of identification of injection-production thief zone.The integrated identification method of injection-production thief zone established in this study provides a more intuitive and richer reference for the identification of thief zone in water drive oilfield,and can further improve the effectiveness and pertinence of potential tapping measures.