Study On Well Pattern Adjustment Technology For Bin X Block In High Water Cut Stage

Geological reserves of sandstone reservoir with fluvial facies account for 65.7%of total geological reserves in Binnan Oil Production Plant,which plays an important role in development of oil-gas resources of the plant.At present most sandstone units have entered the stage of high water cut development.Being affected by reservoir heterogeneity and other complex geological characteristics,the distribution status of remaining oil of partial sandstone reservoir has grown ever more complex,while existing well pattern and well spacing cannot meet actual development demands.In this way,scientific and reasonable well pattern adjustment in bed series is of great importance for long-term and efficient reservoir development.Bin X block can be classified as heterogeneous sandstone reservoir with fluvial facies.Since it has been developed in 1986,three stages of flexible development,waterflood development of inverted nine-spot pattern as well as improvement and adjustment of local flattened well pattern have passed through.Due to poor physical properties of reservoir,the productivity of single well is relatively low in this block while flooding pattern is also unreasonable with low degree of well pattern control,thus sufficient and efficient function has not been realized all the time.Based on the analysis of fundamental data,this thesis aims at research on geological characteristics of oil reservoir in terms of division and correlation of strata,structural features,physical properties of reservoir,fluid properties and other aspects.On the basis of comprehensive evaluation of reservoir development effects in the block,numerical simulation model of this block has been established,in which distribution rule of remaining oil is described and potential area is also confirmed.By way of reservoir engineering methods,development mode,division and reorganization of bed series along with well pattern and well spacing are optimized,simultaneously waterflood development of inverted nine-spot pattern for one set of bed series with 220m×310m has also been adopted.On account of reservoir characteristics and fluid seepage law,by combination of limit parameters study of economic policies,injection-production parameters are optimized and well pattern adjustment schemes are designed,while new added recoverable reserves are 23×10~4t.Index forecast shows that recovery degree will reach 20.7%with cumulative oil production in 19×10~4t after fifteen years.The research results play an important guiding role in improving development effects of target block,meanwhile provide references for well pattern optimization of reservoir formation of the same type.