摘要
将CO_(2)注入地下油藏,可以实现提高原油采收率与CO_(2)地下永久埋存的“双赢”,是最具应用前景和经济效益的“碳中和”有效手段之一。为了有效评价CO_(2)驱油效率,以及准确预测CO_(2)地质埋存量与长期安全性,必须对多孔介质中CO_(2)-油扩散机理进行深入的理论和实验研究。该文利用低场磁共振(NMR)技术实现CO_(2)-油扩散过程的原位动态监测,通过纯相位编码SE-SPI脉冲序列得到溶液随时间和位置变化的一维质子密度曲线,进而得到油相膨胀系数、CO_(2)无量纲浓度等参数;基于菲克第二定律构建了考虑溶液体积膨胀的物理模型,采用非迭代有限体积法计算得到随时间和位置变化的CO_(2)扩散系数,为多孔介质内气-液扩散参数原位测量提供了重要的理论方法与实验数据,对CO_(2)提高石油采收率与地质埋存工程设计、安全性和经济性评价具有重要指导意义。
Injecting CO_(2)into underground oil reservoirs can realize the“Win-win”between enhanced oil recovery and CO_(2)underground permanent storage,which is one of the most effective means of“Carbon neutrality”with the most application prospects and economic benefits.In order to effectively evaluate the CO_(2)flooding efficiency,and accurately predict the CO_(2)geological storage volume and long-term safety,it is necessary to conduct in-depth theoretical and experimental research on the diffusion mechanism of CO_(2)-oil in porous media.In this paper,the in-situ dynamic monitoring of CO_(2)-oil diffusion processis realized by low-field magnetic resonance(NMR).The one-dimensional proton density curve of solution with time and position is obtained through pure phase encoding SE-SPI pulse sequence,and then obtain oil phase expansion coefficient,CO_(2)dimensionless concentration and other parameters.Based on Fick’s second law,a physical model considering the volume expansion of the solution is constructed.The non-iterative finite volume method is used to calculate the CO_(2)diffusion coefficient that changes with time and position,which provides important theoretical methods and experimental data for in-situ measurement of gas-liquid diffusion parameters in porous media,and has important guiding significance for the design,safety and economic evaluation of CO_(2)to improve oil recovery and geological storage engineering.
作者
赵越超
毛晓坤
黄明星
宋永臣
ZHAO Yuechao;MAO Xiaokun;HUANG Mingxing;SONG Yongchen(Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education,Dalian University of Technology,Dalian 116024,China)
出处
《实验技术与管理》
CAS
北大核心
2022年第6期19-23,共5页
Experimental Technology and Management
基金
国家自然科学基金项目(52076030,51606018)
中央高校基本科研业务费(DUT19TD29)。
关键词
CO_(2)扩散系数
多孔介质
低场核磁共振
纯相位编码
CO_(2)
diffusion coefficient
porous media
low-field nuclear magnetic resonance
pure phase encoding
