中文摘要：

碳酸盐岩存在裂缝发育,先期水驱时,裂缝的高导流能力致使注入水充满了大部分裂缝,高含水与高效开发产生了深刻的矛盾。注气能够保持地层压力,波及效率较水驱高。为评价CO2的驱油效果,用正五点法单元井网,应用数值模拟软件,对华北任丘裂缝性底水潜山油藏CO2驱注气参数进行优化,主要包括段塞大小优化、注气速度优化、气水交替中的小段塞优化、气水比优化。结果表明：注气能够有效开发裂缝性油藏,在达到混相条件的基础之上,油藏含水率为90%时以500m3/d的速度注入气水比为0.5的10%HCPV×3的段塞后,以5m3/d的速度水驱至含水率上升至95%时,提高采收率幅度为3.78%。

英文摘要：

Because of high diverting capacity of fractures,which are developed in carbonate reservoirs,most of fractures are filled by injection water in early stage of water flooding,to have a severe contradiction between high water-cut and high efficiency development.Gas injection can maintain the formation pressure and its displacement efficiency is higher than that of water flooding.In order to evaluate displacement efficiency of CO2 flooding,injection parameters of CO2 flooding,which is conducted in Huabei Renqiu buried-hill fractured reservoirs with bottom water,were optimized by using numerical simulation under five-spot well pattern.These parameters are following as：slug size of injection gas,injection rate,small slug size of water-alternating-gas （WAG） injection,and WAG ratio.The results show that gas injection can effectively develop the fractured reservoirs.On the basis of reaching miscible condition,after 10%HCPV×3 slugs with a 0.5 of gas-water ratio was injected by 500m3/d when water cut was 90%,water was injected by 5m3/d until water cut reachs to 95%, to achieve 3.78% of oil recovery rate.