Carbon dioxide (CO₂) storage in geologic formations is an attractive means of reducing greenhouse gas emissions. The main processes controlling the migration of CO₂ in geological formations are related to convective mixing and geochemical reactions. The effects of heterogeneity on these coupled processes have been widely discussed in the literature. Recently, special attention has been devoted to fractured geological formations that can be found in several storage reservoirs. However, existing studies on the effect of fractures on the fate of CO₂ neglect the key processes of geochemical reactions. This work aims at addressing this gap. Based on numerical simulations of a hypothetical reservoir, we explore the effect of fracture properties and topology on the domain's storage capacity at different rates of CO₂ mineral dissolution. It is found that the fractures not only can help the mixing convection and reaction process in the domain but also may play a restrictive role in entering dissolved CO₂ and hinder the plume fingers from growing. The hypothetical case is relevant in providing preliminary understanding but can show varying degrees of geological realism. For more representative geology, we investigate the migration-dissolution of buoyant CO₂ on a large-scale outcrop of a volcanic basalt rock formation. The results show that neglecting thin fractures can significantly affect the predicted amount of trapped CO₂. The storage capacity is more sensitive to heterogeneity at low dissolution rates. The findings are useful for the management of CO₂ sequestration in fractured domains.

地质构造中的二氧化碳 (CO ₂ ) 储存是减少温室气体排放的有吸引力的手段。控制地层中CO ₂运移的主要过程与对流混合和地球化学反应有关。文献中广泛讨论了异质性对这些耦合过程的影响。最近，特别关注可以在几个储层中发现的裂缝地质构造。然而，现有的关于裂缝对 CO ₂归宿影响的研究忽略地球化学反应的关键过程。这项工作旨在解决这一差距。基于对假设储层的数值模拟，我们探索了在不同 CO ₂矿物溶解速率下裂缝特性和拓扑结构对域存储容量的影响。研究发现，裂缝不仅有助于区域内的混合对流和反应过程，而且可能对进入溶解的CO ₂起到限制作用，阻碍羽状指的生长。假设案例与提供初步了解有关，但可以显示不同程度的地质真实性。对于更具代表性的地质，我们研究了浮力 CO ₂的迁移溶解在火山玄武岩地层的大规模露头上。结果表明，忽略薄裂缝可以显着影响捕集CO ₂的预测量。在低溶解速率下，存储容量对异质性更敏感。这些发现对于管理断裂域中的 CO ₂封存很有用。