Research On Identification Method Of Dominant Seepage Channel Based On Oilfield Development Performance Data

In the long-term waterflooding development process of sandstone reservoir,due to high-intensity waterflooding erosion,the development of dominant seepage channels becomes more and more serious,resulting in a large number of injected water invalid circulation and low reservoir recovery.After the formation of the dominant seepage channel,the characteristics of production performance data are obvious,and the parameters closely related to its development are water injection,pressure value,liquid production and so on.Because the accuracy of well performance data is not high and the amount of data is small in the process of development,this paper uses the gray correlation analysis method and fuzzy comprehensive evaluation method to make full use of the dynamic production data of the reservoir,excavate the known information,extract valuable information,and 28 well groups with dominant seepage and 23 well groups without dominant seepage were identified.The traditional grey correlation analysis method and grey entropy correlation analysis method are adopted,and the dynamic data of the whole well and the stratified section are divided into short,medium and long time windows for comprehensive analysis.The correlation coefficient is used to characterize the correlation degree between oil and water wells,so that the dominant seepage channels can be more accurately identified.After analyzing the dynamic data of oil and water wells with the well as the center,the verification is carried out with the well as the center.If the two results are consistent,the result is determined as the final result.If the two results are inconsistent,the final result is determined by analyzing again.Using the fuzzy comprehensive evaluation method to synthesize the development performance data of the actual work area,14 dynamic influencing factors of water wells and oil wells are determined,and then the subjective weight and objective basic weight are used to determine the comprehensive weight of each factor.Through the comprehensive evaluation model,the evaluation matrix is constructed to make a reasonable comprehensive evaluation,and finally the identification of the dominant seepage channel is realized.The practical application results show that the calculation results of the model are close to the actual production,which provides theoretical basis and effective technical support for judging and identifying the dominant seepage channels.