纳米尺度下液体的流动机理研究进展

Advances in nanoscale liquid flow mechanisms

页岩储层的储集空间主体为纳米级孔隙-裂隙系统,仅在局部发育微米—毫米级孔隙。随着以页岩油气、致密油气为代表的非常规油气资源成为全球油气勘探开发的新热点,纳米尺度下的液体流动机理研究引起了国内外学者的广泛关注。通过大量的文献调研,对纳米尺度下液体的流动特征进行了系统总结,分析了目前常用的物模实验、分子动力学模拟和直接Monte Carlo模拟等研究手段的基本原理和优缺点,并从实验和模拟两大方面介绍了纳米孔隙内液体流动机理研究的最新进展及成果。在此基础上,探讨了纳米尺度下液体流动机理研究对页岩油勘探开发的启示,指出分子动力学模拟方法是开展页岩储层纳米级孔隙系统内原油流动机理研究的必然选择,同时需要进一步推进纳米尺度流动的实验方法研究。

Shale pore space is mainly composed of nanoscale pore-fracture network, whereas the micrometer/millimeter-scale pores only exist locally. As unconventional resources such as shale oil/gas and tight oil/gas are becoming the emerging highlights of the global exploration and development, the studies on microscale/nanoscale liquid flow mechanisms are drawing the worldwide attentions. After a thorough literature review, the features of nanoscale flow are systematically summarized, and the basic principles, advantages and drawbacks of the commonly-used investigation methods, such as experiments, molecular dynamics and direct simulation Monte Carlo, are analyzed. Then the most recent advances and conclusions associated with this topic are also introduced from the perspectives of both experimental and simulation. Finally, the enlightenments of nanoscale liquid flow study on the exploration and development of shale oil are also discussed. It is pointed out that molecular dynamics is the inevitable choice for the study of oil transport through nanoscale pore systems in shales, and the techniques for nanoscale flow experiments should also be promoted.