用微观模型组合实验研究最低吸水层渗透率

利用不同微观模型之间的物性差异及其直观性的特点,设计了微观模型组合实验,模拟油层注水,以研究储层非均质对油水运动的影响。通过模型组合实验,可以确定一个合注层段内不吸水小层的渗透率下限,即最低吸水层渗透率K_wmin,研究K_wmin与合注层段中最大渗透率值K_max及注水压力梯度之关系,从而可以进一步根据油层的实际注水压力梯度及用该井取心、测井资料确定的渗透率剖面,求取一个合注层段、一口井、一个油藏的最低吸水层渗透率。最低吸水层渗透率值可以用来进行油藏注水开发效果分析,研究油层剩余油分布。应用K_wmin对鄯善油田三间房组油层部分注水井合注层段的吸水状况做了初步分析,获得了比较满意的结果。可以预料对最低吸水层渗透率的深入研究,将获得该参数更广泛的用途。

STUDY ON THE MINIMUM PERMEABILITY OF WATER DRAWING LAYER-BY USING MULTIMODEL EXPERIMENT

Multimodel experiment simulating reservoir water flooding and made up of several different models in physical property is recommended to study the effect of heterogeneity of a reservoir in flooding process. A new parameter - the minimum permeability of water drawing layer, K_wmin of multilayer-injected interval was measured by multimodel experiment and the relations among K_wmin and maximum permeability of multilayer-injected interval and water flooding pressure gradient were determined by which the K_wmin of other wells of the reservoir can be estimated. It is found that the K_wmin is very helpful to predict the water-flooding effect of a reservoir and the distribution of residual oil. The satisfactory results from application of K_wmin presented in this paper were obtained in Sanjianfang reservoirs, Shanshan Oilfield. It is obviously that further study will lead to extensive application of this new parameter.