缝洞型碳酸盐岩油藏注水驱油提高采收率研究

Y油田为缝洞型碳酸盐岩油藏,油藏复杂的地质特征决定了其开发模式有别于常规砂岩油藏.为了有效提高Y油田采收率,利用Eclipse数值模拟软件建立了地质模型,对水平井长度、射孔间距及酸压缝长等油藏产能影响因素与转注时机、注采比以及关井时间等注采参数进行了优化.结果认为:对于Y缝洞型碳酸盐岩油藏,水平井水平段长度为500m、射孔间距为20m或酸压规模为100m时,累计产油量可达到最大值;压力降至废弃压力时进行转注,可获得最大采收率;周期注采比等于1时,周期时效与累计增油量达到最大值;关井时间为8天时,采收率提高幅度最大.

Study On Enhanced Oil Recovery by Water Flooding in Fractured-Vuggy Carbonate Reservoirs

Y oilfield is a fractured-vuggy carbonate reservoir.Its complex geological characteristics determine that its development model is different from that of conventional sandstone reservoirs.In order to effectively improve the recovery of Y oilfield,the Eclipse numerical simulation software was used to establish a geological model,and the injection-production parameters such as horizontal well length,perforation spacing and acid fracturing fracture length,injection-production ratio and shut-in time were optimized.The results show that for Y fracture-cave carbonate reservoir,the cumulative oil production can reach the maximum when the horizontal section length of horizontal well is 500 m,the perforation spacing is 20 m or the acid fracturing scale is 100 m;when the pressure drops to the abandoned pressure,the maximum oil recovery can be obtained by injection;when the cyclic injection-production ratio is equal to 1,the cyclic aging and cumulative oil increment can reach the maximum.When the shut-in time is 8 days,the recovery rate increases the largest.