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
王牧原 1李勇 2吴克柳 1陈掌星 3李靖 1冯东 1朱清源 1郭世强1
作者信息
- 1. 中国石油大学(北京)油气资源与探测国家重点实验室,北京 102249
- 2. 中国石油勘探开发研究院,北京 100083
- 3. 中国石油大学(北京)油气资源与探测国家重点实验室,北京 102249;卡尔加里大学 化学与石油工程系,加拿大 阿尔伯塔 T2N1N4
- 折叠
摘要
孔隙型碳酸盐岩储层非均质性强且孔隙类型多样,水驱采出程度差异较大,其主控因素尚不明确.基于孔喉频度分布曲线定性分类了储层微观孔隙结构,通过数字岩心技术建立了微观孔隙结构定量表征的方法,明确了中东某地区孔隙型碳酸盐岩孔喉特征,并开展水驱油室内物理实验,阐明了不同类型岩心采出程度差异及其主控因素.结果表明:①研究区储层微观孔隙结构可分为偏粗单峰型、偏细单峰型Ⅰ、偏细单峰型Ⅱ、偏粗双峰型及多峰型,储集性能与岩心均质性无显著关系,非单峰型的单相渗流能力优于单峰型,且单峰型随岩心均质性增强,单相渗流能力变差.②非单峰型的平均配位数和平均孔喉比均高于单峰型,且单峰型随着岩心均质性的增强,平均配位数和平均孔喉比降低.所有类型随喉道半径增加,孔喉比上限呈下降趋势;随孔隙半径增加,配位数上限呈指数型上升.③宏观上,岩心均质性为驱油效率主控因素;微观上,非单峰型在大孔喉处的高连通性以及小孔喉处的大孔喉比是导致其驱油效率显著低于单峰型的根本原因,且孔喉尺寸是单峰型驱油效率的重要影响因素.
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引用本文复制引用
基金项目
国家自然科学基金面上项目(52174041)
北京市自然科学基金面上项目(3232029)
国家自然科学基金(52104051)
&&(51874319)
出版年
2024
国家科技期刊平台
NSTL
万方数据