裂缝性特低渗透储层注水开发井网的优化设计

Optimal Design of Waterflooding Well Patterns in Fractured Ultra-low Permeability Reservoirs

裂缝性特低渗透储层注采井网模式只有适应裂缝发育方向与强度,同时建立有效的驱替压力系统才能合理有效开发。以甘谷驿油田唐80井区三叠系延长组长6油层组裂缝性特低渗透油层为例,研究认为:原近于圆形的反九点丛式井网严重不适应裂缝性特低渗透储层渗流特征是造成开发效果差的主要原因;菱形反九点为首选初始基础井网,合理排距为140m,井距为500m;在开发后期适时调整为矩形反五点井网或排状注采井网,实现平行裂缝方向注水,垂直裂缝方向驱油。

Well patterns of fractured ultra-low permeability reservoirs,which should be appropriate for fracture growing direction and intensity and with effective displacement pressure system,can be used for rational and effective development,oil bed Chang 6 in Triassic Yanchang Formation in wellblock Tang 80 of Ganguyi Oilfield is taken for example,a study indicates that original inverted nine-spot cluster well-pattern is not satisfied with the characters of fractured ultra-low permeability reservoirs,which is the major cause of poor effect of production,a diamond-shape inverted nine-spot is initially selected for a basic well pattern,rational row distance is 140m, well space is 500m,at the late stage of development it is adjusted into a rectangular inverted five-spot well pattern or row injection-production well pattern,by which water injection in horizontal direction and displacement in vertical direction are implemented.