一常见气体及CO_2在岩心模型和细长管模型上的驱油对比

Comparison of oil displacement by gases and CO_2 using core model and slim-tube

对地层驱油过程进行物理模拟,分别借助常规低渗碳酸盐岩心模型和细长管模型对比常见气体(氮气、甲烷、石油伴生气)及液态CO_2的驱油效果。结果表明:两种模型对氮气驱油能力的评估结果几乎一致(分别为21%和19.1%);随着流体与原油混溶性的增加,两种模型评估结果的差异变大,对可与原油混溶的液态CO_2的评估结果分别为52%和94.8%;仅基于岩心模型的常规驱替实验并不能完全评估气体/溶剂的驱油能力,尤其对混相驱油剂的评价结果是不可靠的。

The physical modeling of reservoir processes was conducted. A comparative study of oil displacement efficiency was investigated using gas agents （nitrogen, methane,associated petroleum gas） and liquid CO2 with the core models of low- permeability carbonate reservoir and slim-tube. It is shown that the two models have the similar oil displacement coefficient for nitrogen （21% and 19. 1%）. With the increasing miscibility of fluids in crude oil,the difference betwe en the results of the two models becomes larger. For liquid carbon dioxide,which is miscible with oil,evaluation results of the two models are 52% and 94. 8% , respectively. Therefore,it is concluded that the normal displacement experiment using core models cannot evaluate the oil displacement efficiency of gas agents and solvents. Especially the evaluation results for the mixed oil dis-placement agents are unreliable.