In this study the delicate invasion nature of pure supercritical carbon dioxide sCO₂, alongside the determination of the main boundaries for sCO₂ flow-pattern transitions inside the nanopores of treated 3D-porous matrix are investigated numerically. Sensitivity parameters under various sCO₂ injection rates and flow regimes are discussed. The numerical outcomes are relied on MRT-Lattice Boltzmann method utilized in this study, while unyielded zones and inactive pores are identified by 3D voxels. The structural complexity of near-spherical porous matrices is addressed to study the flow behaviors of sCO₂. This micrometer media followed a spherical approach with a studied random arrangement. The lengths of the computational domain in transverse directions were set to be five times as long as the highest diameter $d_{\mathrm{p}}$ of the solid matrix, (highest $d_{\mathrm{p}}$ $=$ 50 nm), while the longitudinal direction was set to be 40 times $d_{\mathrm{p}}$. The simulations are carried out for a wide range of initial sCO₂ velocities, which adimensionally denoted by Reynolds values. As well, unsteady-state flow regimes are adopted for precise interpretations of complex flow patterns and interactions in the nanopores. This numerical methodology allowed the study of the injection boundaries toward each flow regime of sCO₂ inside the complex porous structure. Based on the above analysis, a primary flow-pattern chart is established for the invasion of sCO₂.

在这项研究中，对纯超临界二氧化碳 sCO ₂的微妙侵入性质，以及处理过的 3D 多孔基质的纳米孔内 sCO ₂流动模式转变的主要边界的确定进行了数值研究。讨论了各种 sCO ₂注入速率和流态下的灵敏度参数。数值结果依赖于本研究中使用的 MRT-Lattice Boltzmann 方法，而未屈服区域和非活动孔隙由 3D 体素识别。解决近球形多孔基质的结构复杂性以研究 sCO ₂的流动行为. 这种微米介质遵循球形方法，并具有研究的随机排列。横向计算域的长度设置为最高直径的 5 倍$d_{\mathrm{磷}}$ 的固体基质，（最高 $d_{\mathrm{磷}}$ $=$ 50 nm)，而纵向设置为 40 倍 $d_{\mathrm{磷}}$. 模拟是针对大范围的初始 sCO ₂速度进行的，这些速度由雷诺值在量纲上表示。同样，采用非稳态流态来精确解释纳米孔中复杂的流动模式和相互作用。这种数值方法允许研究复杂多孔结构内sCO _{2 的}每个流态的注入边界。基于以上分析，建立了sCO ₂侵入的主要流型图。