Fundamental understanding of processes controlling geological carbon sequestration (GCS) requires flow and transport modeling in well-characterized aquifer sedimentary deposits. We use three-dimensional, heterogeneous models based on new field studies which incorporate the most important aspects of multiscale architecture in fluvial aquifers. In addition, we use the associated facies-dependent constitutive relations for both relative permeability and capillary pressure curves and their hysteresis. The novelty of this work is to evaluate how CO₂ fate and transport is controlled by (1) the spatial organization, volume proportions, and connectivity of sedimentary facies types, (2) facies-dependent constitutive relations and their hysteretic behavior, and (3) presence and/or absence of dissolved components such as methane (CH₄) in brine. Model results suggest that the amounts of snap-off and solubility trapping are enhanced by increasing the volume proportion and degree of connectivity of high-permeability facies types. Results also demonstrate that ignoring relative permeability hysteresis leads to underestimation of snap-off trapping and overestimation of solubility trapping. In contrast, neglecting capillary pressure hysteresis (i.e., non-hysteretic P_c) results in overestimation of snap-off trapping and underestimation of solubility trapping. If capillary pressure is totally neglected (i.e., P_c = 0), the amount of trapped CO₂ by snap-off and dissolution are, respectively, overestimated and underestimated. Competitive CO₂ and CH₄ dissolution in brine results in exsolution of CH₄ from the aqueous phase into the gaseous phase. Facies connectivity and constitutive relations are also critical for the transport of exsolved CH₄. However, disregarding dissolved CH₄ leads to overestimation of CO₂ trapping capacities.

对控制地质碳固存（GCS）的过程的基本了解要求在特征明确的含水层沉积物中进行流动和传输模型。我们根据新的田间研究使用三维异质模型，这些模型结合了河流含水层中多尺度体系结构最重要的方面。此外，我们将相关的相依本构关系用于相对渗透率和毛细管压力曲线及其滞后。这项工作的新颖性是评估CO ₂如何命运和运移受以下因素控制：（1）沉积相类型的空间组织，体积比例和连通性；（2）相相关的本构关系及其滞后行为；（3）溶解成分的存在和/或不存在，例如在盐水中的甲烷（CH ₄）。模型结果表明，通过增加高渗透相类型的体积比例和连通度，可以增加速溶和溶解性捕集的量。结果还表明，忽略相对磁导率滞后会导致低估捕集阱和高估溶解度阱。相反，忽略毛细管压力滞后（即，非滞后的P _c）导致高估捕集阱捕集和低估溶解度捕集。如果完全忽略了毛细管压力（即P _c  = 0），那么通过急速溶出和溶解而捕获的CO ₂量将分别被高估和低估。在盐水中竞争性溶解CO ₂和CH ₄导致CH ₄从水相释放到气相中。相的连通性和本构关系对于溶解的CH ₄的运输也至关重要。但是，忽略溶解的CH ₄会导致高估CO _2的捕集能力。