The Research On Dominant Migration Channels Of The Baodaowan Formation Reservoir In Di12 Well Block Of The Junggar Basin

In the long term water injection development process,under the influence of reservoir structure,deposition,diagenesis and late water injection,the pore structure of the reservoir has changed dramatically and gradually formed dominant migration channels.The existence of them can lead to ineffective circulation of water from the injection well,thus the other part of the reservoir is difficult to be involved,which seriously affects the oil displacement efficiency.It is an urgent problem to identify dominant migration channels effectively and adopt suitable technologies to block them in the stage of middle and high water cut.The research focuses on dominant migration channels of the Di 12 well block,comprehensively applying the reservoir geology theory and method,geology,well logging,oil testing and development of dynamic data.Firstly,the research summarizes characteristics of dominant migration channels that showing on the well logs,geological model,the injection wells and oil wells;secondly,four factors that controls its forming: sedimentary facies,the surface of diagenesis,the fracturing of reservoirs and the production through water injecting are analyzed;and then choosing the grey correlation theory and the tracer technique to predict the possible distribution of dominant migration channels.Synthetically analysis show that dominant migration channels are distributing in the J₁b₁^1-2?J₁b₁^1-3?J₁b₁^1-4 vertically and their extension directions are compliance with the directions of fractures.All of this provides the next step for water shutoff and stratified water dynamic allocation and improves the sweep efficiency of the injected water.