Study On The Production Influence Of The Casing Damaged Well In SaPu Reservoir Of The Central West In Daqing Oilfield

Casing damaged well will cause production loss,destroy the balance of injection and production system,reduce the recoverable reserves and recovery rate,and fail to accept the detection data,which will seriously affect the stable production and development effect of the oilfield.Therefore,it is necessary to carry out research on the production impact of casing dameged wells,analyze the influence mechanism of seepage field in casing damaged well,and statistically study the production capacity change and recovery efficiency change of casing dameged wells.In this paper,numerical simulation and reservoir engineering theory are used to study the changes of sweep area and fluid and oil production in five point well pattern,inverted nine point well pattern and inverted seven point well pattern.Based on the ideal models of different well patterns,30 ideal models,including the number of casing dameged wells,the type(oil well)and the location,were developed to study the influence of the flow field distribution and the influence of water flooding on the well group.As for as the different wells type,location,and number in the different pattern,studies have shown that the proportion of affected area loss of casing damaged wells is directly proportional to the ratio of oil and water wells in the well pattern itself,whose size relation is the inverted nine point pattern > inverted seven point pattern > five-point pattern,loss ratio is 51.26%,45.23% and 41.84% respectively when watercut come up to 98%,and affected area of the casing damage wells ratio is inversely proportional number of oil and water wells.The change of productivity after casing damage of a well or well in an ideal model showed that well group daily fluid loss ratio is 35.39%,28.26% and 18.33% respectively of the inverted nine,seven,five point well pattern,when watercut come up to 98%,but casing damage of oil wells well group daily fluid loss ratio is 2.87%,0.58% and 0.52%,respectively.Using the empirical formula method,the law of water drive curve and the law of diminishing curve,which is compared with the model recovery ratio,the law of water drive curve and the law of diminishing curve prediction accuracy is higher,decline curve application is wider,the calculation for inverted five,seven and nine ponint pattern water well casing damage loss recovery rate was 2.78%,8.52% and 9.16%,oil well casing damage loss recovery rate was 4.82%,2.20% and 2.18%,the same as the production of casing damage were preliminarily.The combination of numerical simulation and reservoir engineering method can quickly and quantitatively evaluate the impact of casing damage well on production,and provide a theoretical basis for the comprehensive treatment of casing damage well.