聚驱后剩余油分布的大平面驱油实验及荧光分析  

Studies of Remaining Oil Distribution After Polymer Flood by Large Planar Core Flooding and Core Section Fluorescence Analysis

作　　者：吴家文[1] 井洋[1] 王京博[2] 吕媛媛[3] 宋考平[1] 

机构地区：[1]大庆石油学院石油工程学院,黑龙江大庆163318 [2]中国石油辽河油田分公司勘探开发研究院试验技术研究所,辽宁盘锦124010 [3]中国石油辽河油田分公司勘探开发研究院油田开发所,辽宁盘锦124010

出　　处：《油田化学》2008年第1期46-50,共5页Oilfield Chemistry

基　　金：国家自然科学基金重点资助项目“低渗透油层提高驱油效率的机理研究”(项目编号50634020);黑龙江省杰出青年科学基金项目“油层多孔介质内纳观渗流界面作用力研究”资助

摘　　要：通过大平面人工均质岩心驱油和驱油后储层岩心磨片荧光分析,针对大庆油田研究了聚合物驱后剩余油分布。人工均质岩心渗透率2μm2,孔隙度0.263,几何尺寸(cm)为60×60×2.4,由埋置的81对微电极测量81个点处的电阻率,计算各该处含水饱和度,求得含油饱和度。大平面模型经清水驱油后,注入聚合物0.57 PV×1000mg/L,再继续水驱,绘制了采收率和含水率曲线,及水驱、注聚、后续水驱结束时平面上岩心含油饱和度分布图。含油饱和度沿主流线(一条对角线)近似对称分布,主流线上含油饱和度最低,水驱后为32.0%,注聚并后续水驱后为21.5%,波及系数分别为0.960和0.985。取自大庆不同储层的两组各两支岩心,一支水驱油,另一支实施水驱—注聚—后续水驱,驱替后在注入端、中间、采出端各取一横剖面制成磨片,用荧光分析法测定剩余油饱和度并计算其概率密度。与水驱后岩心相比,聚驱后两组岩心每一剖面的剩余油饱和度均降低,低剩余油饱和度(<30%)部分所占比例增大,高剩余油饱和度部分所占比例减小,最大剩余油饱和度值降低,其中一组岩心的最小剩余油饱和度值减小。The remaining oil distribution after polymer flood is studied through large planar homogeneous artificial core （LPHAC） flooding and fluorescence analysis of reservoir core sections. The LPHAC has permeability 2 μm^2, porosity 0. 263, and geometric size （in cm） 60×60×2.4 and is made with 81 pairs of mieroelectrodes placed in lines to measure the electric resistance values, from which water and oil saturations are calculated. The LPHAC is flooded by water, 0.57 PV of 1000 mg/L polymer solution, and water successively, the oil recovery and watercut curves are demonstrated and the contour maps of oil saturation after water flooding, polymer injection, and successive water rico：ling are constructed. The distribution of oil saturation is approximately symmetric about the principal flowline, one of the diagnols of the core; in the principal flowline, the lowest values of oll saturation of 32.0% after water flood and of 21.5% after polymer injection and successive water flood and a sweep efficiency of 0. 960 and 0. 985, respectively, are observed. In reservoir core flooding experiments, two core groups are taken and each group is consisted of two cores from an oil reservoir in Daqing： one for water flooding serving as reference and another for polymer （water-polymer-successive water） flooding. From every core flooded, three polished sections in starting,medium, and ending areas are made to measure remaining oil saturation, Sor by fluorescence analysis and to determine its probability density. For the cores polymer flooded in comparison with the cores water flooded, the Sor values on every section studied is decreased, the proportion of low Sor（ 〈 30% ） areas is increased and of high Sor areas--decreased, the highest Sor values are decreased and, for one core group, the lowest So, values--decreased.

关 键 词：聚合物驱 剩余油分布 油饱和度 大平面均质岩心 储层岩心 电阻率 荧光分析 大庆油田 

分 类 号：TE327[石油与天然气工程—油气田开发工程] TE357.46