Abstract: For the problem of CO₂ channeling along the fracture direction in 203 well area of Qiaojiawa block, Yanchang oilfield, CO₂  flooding experiment under immiscible and miscible condition is carried out with homogeneous and heterogeneous artificial core. Meanwhile, heterogeneous gas channeling coefficient and oil displacement efficiency lower amplitude are introduced to study the influence of heterogeneity gas channeling on CO₂  flooding quantitatively and analyse the influence of permeability differential and phase behavior on heterogeneity gas channeling. The experiment results show that the influence of permeability differential on heterogeneity gas channeling is obvious and there is a certain sensitive boundary. The sensitive boundary of permeability differential is about 15. It is sensitive when the permeability differential is lower than 15, and heterogeneous gas channeling coefficient and oil displacement efficiency decrease rapidly with the increasing of permeability differential. It is nonsensitive when the permeability differential is greater than 15. The relative strength of fingering gas channeling and heterogeneity gas channeling is bounded to permeability differential of K(3

Key words: Heterogeneity,   , Gas channeling,    , CO₂,   , Gas channeling coefficient

摘要： 针对延长油田乔家洼区块2 0 3井区CO2 驱过程中, CO₂ 沿储层高渗条带方向发生气窜的问题, 采用均质和非均质人造岩心开展CO₂ 非混相和混相驱油实验, 引入非均质性气窜系数和驱油效率降低幅度两个评价参数, 以量化研究非均质性对CO₂ 气窜的影响程度, 并分析渗透率级差和CO₂ 驱油相态对非均质性气窜的影响。结果表明, 渗透率级差对非均质性气窜影响明显, 且非均质性气窜对岩心渗透率级差存在一定的敏感界限, 该界限渗透率级差值为1 5。当渗透率级差小于1 5时为敏感区, 非均质性气窜系数和驱油效率降低幅度随渗透率级差的增大迅速增大; 渗透率级差大于1 5时为非敏感区。指进气窜和非均质性气窜的相对强弱以渗透率级差值K( 3

关键词: 非均质性,  , 气窜,  CO₂ ,  , 气窜系数