中文摘要：

二氧化碳地质封存是一个新型的地质工程热点问题，仍然面临诸多挑战，其中之一是如何利用纳米材料与技术提高储层的可注入性和有效储量．本文将纳米流体的对流一扩散方程与三维多孔介质多相流动模式相结合，初步建立多孔介质中超临界CO2纳米流体多相流动理论模型，采用高精度时空守恒元／解元（CE／SE）算法，模拟非均质储层中CO2的前缘迁移和分布特征．计算结果显示，疏水纳米粒子减弱流体边界层内流动的剪切力，增强（CO2在边界层内的移动性能，即纳米粒子在流体边界层减阻机理；同时，纳米粒子增强流体内部的剪切作用，促进CO2前缘迁移均匀化．上述结果初步揭示疏水纳米粒子降低了地层非均质性对CO2前缘迁移的影响，可提高CO2有效地质储量．本文提出的纳米流体地质封存概念，对商业化大规模CO2地质封存、深层干热岩地热资源的开发、致密油气藏的高效开发以及提高采收率（EOR）具有意义，同时对纳米材料与技术在环境资源利用及资源高效再生中的应用研究领域具有一定的推动作用．

英文摘要：

CO2 geological storage is a novel hot issue relevant to climat change, facing a variaty of challeges, of which is how to enhance the CO2 injectivity and effective storage capacity bu using the Nano material and technologies. In this article, based on the governing equation of convection-diffusion of Nanofluid coupled with 3D multiphase flow model, the preliminary theoretical model is established for multiphase flows of supercriticat CO2 Nanofluid in porous media. The high resolution space-time conservation element and solution element （CE/SE） method is deployed to simulate the CO2 migration and distribution in the heterogeneous saline reservoir. It＇s found that the involvement of Nano particles eleminates the shear effeetes within fluid boundary layer, and enhances the CO2 mobility through the shear layer. Furthermore, Nano particles increase the interior shear stress in fluids, promoting homogeneous distribution of CO2 front. We prelimilarily find that nanofluids enhance the mass homogeneous transfer of CO2 in the reservoir, and mitigate the negative effects of stratigraphic heterogeneity on the migration and accumulation of the CO2 plume. The effective storage capacity of CO2 is greatly elevated by means of nanofluid geological storage. The concept of Nano fluid geological stirage into saline aquifers may be potentially conducive for lagre scale commercial CO2 geological storage, and useful for exploration of geothermal resources in deep-seated hot rocks, especially for shale gas. Meanwhile, it should devote to promotiing researches on application of Nano material and technology to environmental protection and resource utility, and enhancing the high effective recycle of resources.