Abstract: The flow unit method is used to study behaviors of reservoirs.The interlayer heterogeneous models were designed,according to the characters of detrital reservoir.The water flooding under the same condition of hydrodynamic force was experimented with the differentiated permeability models.The results indicate that the critical index of permeability ratio is 2 for partition of flow unit.All layers flooded effectively in commingled water injection for the reservoirs with permeability ratio less than 2 are taken as a flow unit.The flow path of injected water is independent on the absolute permeability,but on the relative permeability value between layers.The permeability ratio index is brought forward by experimental results and can be a new index for flow unit partition.

Key words: clastic reservoir, flow unit, permeability ratio, interlayer heterogeneity, simulation test

摘要： 根据流动单元渗流特征的定义,设计了层间非均质实验模型,研究了相同水动力条件下不同渗透率级差模型的水驱油渗流规律和水淹规律。实验结果表明,渗透率级差为2是流动单元划分的界限,渗透率级差小于2的非均质储层在合注时各个层位都能被注入水有效驱动的为一个流动单元。注入水自然流动形成的通道不完全是由绝对渗透率决定,而与层位之间渗透率相对大小有关。通过实验论证,提出了流动单元划分的渗透率差异指标。

关键词: 碎屑岩储层, 流动单元, 渗透率级差, 层间非均质性, 模拟实验