砾岩油藏微观结构对聚驱后剩余油影响研究

ANALYSIS ON CHANGEABLE RULES OF REMAINING OIL IN CONGLOMERATE RESERVOIR AFTER POLYMER FLOODING

采用岩心饱和度分析、荧光薄片分析和核磁共振分析方法研究了砾岩油藏不同岩性及微观孔隙结构与聚驱后剩余油分布规律的关系,研究表明,纵向上正韵律油层中顶部驱油效率低,剩余油饱和度较大,而反韵律油层剩余油分布较均匀。聚合物驱对不同岩性砂砾岩均具有较好的驱油效果,对自由态剩余油驱替效果最好,复模态结构砾岩储集层不利于聚合物驱替束缚态和半束缚态剩余油。不可及孔隙体积对聚合物驱剩余油分布有一定影响,在低渗透砾岩油藏聚合物分子量大容易造成聚合物注不进去,在注聚过程中,应考虑聚合物的分子量与地层渗透率的匹配关系。

With the method of core saturation analysis,the fluorescent thin- section analysis,and nuclear magnetic resonance( NMR) analysis,the changeable rules of remaining oil in conglomerate reservoir after polymer flooding was analyzed. The research has shown that positive rhythm reservoir in the top on the longitudinal displacement efficiency is low,remaining oil saturation is larger,and reverse rhythm reservoir remaining oil distribution is uniform. Polymer flooding of different lithology glutenite have good oil displacement effect,to the free state of remaining oil displacement effect is best,complex modal structure conglomerate reservoir to disadvantage of polymer displacement bound state and half bound state of remaining oil. And small pore volume of polymer flooding has a certain influence,remaining oil distribution in the low permeable conglomerate reservoirs,polymer molecular weight cause polymer note,in the process of polymer injection,the matching relation between the molecular weight of polymer and formation permeability should be considered.