Well Pattern Reconstruction And Effect Appraisal For The Second Round And The Third Round Infill Well In Beiyierpaixi Oil Field

Beiyierpaixi oil field of water flooding into extra high water cut period,effected by its own plane heterogeneity stronger,the original well pattern appeared high dispersion remaining oil,injection-production distance between single sand body were not balanced,injection-production relationship was imperfected,such as the contradiction,which has resulted in significant changes in the general pattern of underground oil and water distribution.The original well pattern was signigicatly reduced,it is urgent to study well pattern reconstruction.Before well pattern reconstruction development effect is evaluated in Beiyierpaixi oil field.The evaluation found that the study area at present production decline faster,the water cut higher,the water cut rising faster;control degree and producing degree lower;remaining oil highly dispersion;between single sand body injection-production distance is not balanced,injection-production relationship is imperfected,such as the contradiction.Elaborate geological modeling and numerical modeling.Based on the Petrel geological software,elaborated Beiyierpaixi geological modeling.Eclipse numerical simulation software was used for numerical simulation.After August 2015,the remaining oil is mainly distributed in the thin and poor reservoir of SII1-SII9 and PII,which is necessary to tap the potential of "two or three well pattern reconstruction(mutual perfect injection production relation)".Three kinds of main measures are perforations adding,blank off and to convert oil well to water injection well for well pattern reconstruction.Perforations adding scheme includes 143 oil wells,52 water wells and 1889 perforations adding points;blank off sheme includes 46 oil wells,16 water wells and 263 blank off points;converting 75 oil wells to water wells.From August 2015 to begin well pattern reconstruction,to measure basically completed in October 2016.At present,there are 320 production wells and 247 injection wells,which include 112 polymer injection wells and 135 water injection wells.Well pattern development effect evaluation after reconstruction.(1)In 2015 well pattern reconstruction adjustment,declining rate slow down for water flooding well pattern,increasing extent of cumulative oil production appear low-amplitude increase;rate of descent of yearly rate oil production is diffierent extent mitigated for every oil group,increasing extent of cumulative liquid production tend to be gentle for every oil group of water flooding well pattern,on the whole in a rising trend.Declining rate of water flooding well pattern is reduce from 0.0570 to 0.0529,declining rate of every oil group appear different extent reduce.Water cut of the whole region was 94.70% in October 2016,which was 1.49% lower than that before well pattern reconstruction.At the same time,it can effectively inhibit the increase of water cut rasing rate in every oil group of water flooding well pattern,obvious effects of measures.(2)Taking into account pattern well spacing,the data of fault breakpoints and sedimentary facies of oil and water wells in Beiyierpaixi,a set of calculation method for the connection-between-well database is formed,connection-between-well database of water flooding well pattern and polymer flooding well pattern is determined.Using the connection-betweem-well database,based on computing method of control degree of water flooding well pattern and polymer flooding well pattern,its control degree is determined for 50 layers.After well pattern reconstruction,control degree of water flooding well pattern is improved from 79.23% to 85.77%,which is increased by 6.54 percentage points;control degree of polymer flooding well pattern is improved from 72.13% to 75.90%,which increased by 3.77 percentage points.(3)Using the definition method and water drive curve method is order to study the producing degree of water flooding well pattern in the study area.After well pattern reconstruction producing degree is improved from 39.35% to 43.57%,which is increased by 4.22 percentage points.According to the current production system of oil wells and water wells,and the use of Eclipse numerical modeling software to invariability liquid production,which is order to effect appraisal for medium and long-term development.Reservoir engineering method and mumerical modeling method make sure that after well pattern reconstruction recovery ratio is 44.330%,than before the well pattern reconstruction increased by 0.585 percentage points,to achieve the desired adjustment effect.