Hele—Shaw Cell模型中粘性指进现象的研究Ⅰ.时间对粘性指进的影响

Studies on the viscous fingering phenomenon in hele-shaw cell model I. The effect of the time on discous fingering

在二次采油和三次采油中都存在一种粘性指进现象，它对采收率有很大影响。本工作 设计了一台改进型Ｈｅｌｅ－Ｓｈａｗ Ｃｅｌｌ模型，能模拟采油过程中的这种指进现象，它和油田开采有许多 类似之处。应用分维几何的基本原理，以排出率（Ｓｅ）为目标函数，对随机的复杂的分枝形状图形进行 了数学处理，研究了时间（ｔ）和 Ｓｅ的分枝数目（Ｎ）的影响．结论是在该条件下，分枝数的变化率 （ｄＮ／ｄｔ）对Ｓｅ的影响很大，在粘性指进发展的前、中期，Ｓｅ与 ｔ的关系可用一个数学公式描述： Ｓｅ＝ ０．６０８＋ －０． １６ｔ~０.２４，这一结论对研究聚合物驱油机理，提高采收率有一定的意义。

There are viscous fingering phenomenon in the secondary and the third oil recovery. It had an apparent effect on the recovery efficiency. The viscous fingering phenomenon of oil recovery and the model is very similar to the oil recovery in oil field. The auidental and complicated branch pattern were treatmented by the foundmental principl of fractal geometry and the effect of the time and the branch number on the discharge rate (Se) were studied by using the discharge rate as an object function. The results indicate that the change rate of the branch number had an apparent effect on the discharge rate. During the earlier stage and the medium stage of the viscous fingering, the relation between the discharge rate and the time were described by the mathematical function :Se=0.608 +-0.1608t^0.24 These results are very significant to study the theory of polymer displaling oil and improved the recovery effciency.