Offshore heterogeneous conventional heavy oil reservoirs are mostly developed with irregular area injection-production well patterns.During the high water-cut stage,the problem of uneven planar water flooding becomes ...Offshore heterogeneous conventional heavy oil reservoirs are mostly developed with irregular area injection-production well patterns.During the high water-cut stage,the problem of uneven planar water flooding becomes prominent.Adjusting the injection-production pressure difference to achieve planar balanced displacement is a key approach to improve the degree of reserve utilization and reservoir recovery efficiency.Based on streamline numerical simulation,this paper divides the irregular area injection-production well pattern into several injection-production seepage units,with each unit accounting for planar heterogeneity.A calculation method for planar sweep efficiency,considering the starting pressure gradient of heavy oil and non-piston water flooding characteristics,is established using the flow pipe method.By optimizing the injection-production pressure difference of different production wells,the areal sweep efficiency of each injection-production seepage unit tends to be consistent,thereby realizing planar balanced water flooding.Applying this method to the injection-production structure adjustment of Bohai Oilfield B achieves significant effects in water control and oil increment.This method can provide a theoretical basis for the optimization of initial injection-production pressure difference and the adjustment of injection-production structure during the high water-cut stage in heterogeneous conventional heavy oil reservoirs.展开更多
文摘Offshore heterogeneous conventional heavy oil reservoirs are mostly developed with irregular area injection-production well patterns.During the high water-cut stage,the problem of uneven planar water flooding becomes prominent.Adjusting the injection-production pressure difference to achieve planar balanced displacement is a key approach to improve the degree of reserve utilization and reservoir recovery efficiency.Based on streamline numerical simulation,this paper divides the irregular area injection-production well pattern into several injection-production seepage units,with each unit accounting for planar heterogeneity.A calculation method for planar sweep efficiency,considering the starting pressure gradient of heavy oil and non-piston water flooding characteristics,is established using the flow pipe method.By optimizing the injection-production pressure difference of different production wells,the areal sweep efficiency of each injection-production seepage unit tends to be consistent,thereby realizing planar balanced water flooding.Applying this method to the injection-production structure adjustment of Bohai Oilfield B achieves significant effects in water control and oil increment.This method can provide a theoretical basis for the optimization of initial injection-production pressure difference and the adjustment of injection-production structure during the high water-cut stage in heterogeneous conventional heavy oil reservoirs.
