Quantitative water injection of fractured-cavity oil reservoir in carbonate rocks in Tahe oilfield

By using the ant tracking technique and inter well interference test,the quantitative characterization of fine description and connectivity of cave and fracture to realize the relation between cave and fractures was carried out,and the technology of quantitative injection-production pattern of the seam type reservoir was gradually established,which greatly improved the waterflooding efficiency.According to different backgrounds of karst reservoirs,a multi-dimensional injection-production well pattern in weathering crust area,a spatial structure well pattern in underground karst area and a linear well pattern in fault karst area were established,and the differential well pattern construction technology was formed.According to the well pattern construction technology,by using the models of elastic flooding and hydraulic complex flooding,the water injection intensity of bottom water reservoir has been quantified.Based on injection-production corresponding curve,quantitative determination of water injection strength of closed elastic flooding reservoir has been quantified.The water injection cycle is quantified by the response characteristic curve of the tracer.Quantitative calculation of water diversion rate in different directions was realized by means of the comprehensive energy change curve and material balance method.The application results indicate the technology can effectively enhance the recovery degree of waterflooding reservoirs.