油气地质与采收率2024，Vol.31Issue(2)：96-107,12.DOI:10.13673/j.pgre.202304037
孔隙型碳酸盐岩油藏储层微观孔隙结构定量表征及驱油效果评价
Quantitative characterization of microscopic pore structure and oil re-covery evaluation in porous carbonate reservoirs
摘要
Abstract
Porous carbonate reservoirs are characterized by strong heterogeneity and diverse pore types,with significant differences in waterflooding recovery and unclear main controlling factors.Based on the pore throat size distribution curves,the microscopic pore structure of the reservoir was qualitatively classified.Through digital core technology,a method for quantitative characteriza-tion of microscopic pore structure was established to clarify the pore throat characteristics of porous carbonate rocks in a region of the Middle Eastern,and indoor physical experiments on waterflooding were conducted to clarify the differences in the oil recovery of different types of cores and their main controlling factors.The results show that ① The microscopic pore structure of the reservoir in the study area can be classified into coarse unimodal type,fine unimodal type I,fine unimodal type II,coarse bimodal type,and multimodal type.There is no significant relationship between storage performance and core homogeneity;the single-phase flow ca-pacity of non-unimodal type is better than that of unimodal type;unimodal type becomes worse with increasing core homogeneity.②The average coordination number and pore-throat ratio of the non-unimodal type are higher than those of the unimodal type.The average coordination number and pore-throat ratio decreased with the increase of core homogeneity for the unimodal type.The up-per limit of the pore-throat ratio tends to decrease with increasing throat radius for all types,and the upper limit of coordination number increases exponentially with increasing pore radius.③Macroscopically,core homogeneity is the main controlling factor of oil displacement efficiency;microscopically,high connectivity at large pore-throat and large pore-throat ratio at small pore-throat are the fundamental reasons for non-unimodal type to have significantly lower oil displacement efficiency than unimodal type.Pore-throat size is the crucial factor of oil displacement efficiency of unimodal type.关键词
孔隙型碳酸盐岩油藏/微观孔隙结构/数字岩心/定量表征/驱油效率Key words
porous carbonate reservoir/microscopic pore structure/digital core/quantitative characterization/oil recovery分类
能源科技引用本文复制引用
王牧原,李勇,吴克柳,陈掌星,李靖,冯东,朱清源,郭世强..孔隙型碳酸盐岩油藏储层微观孔隙结构定量表征及驱油效果评价[J].油气地质与采收率,2024,31(2):96-107,12.基金项目
国家自然科学基金面上项目"非常规储层纳米孔中水驱气动态润湿机理与传输特性"(52174041),北京市自然科学基金面上项目"非常规储层纳米孔水传输研究"(3232029),国家自然科学基金项目"页岩储层压裂液侵入/反排/滞留机理及其对气井产能影响规律研究"(52104051)和"页岩气有效储渗孔隙跨尺度耦合渗流及产出规律研究"(51874319). （52174041）
