The rate of carbon dioxide (CO₂) dissolution in saline aquifers is the least well‐constrained of the secondary trapping mechanisms enhancing the long‐term security of geological carbon storage. CO₂ injected into a heterogeneous saline reservoir will preferentially travel along high permeability layers increasing the CO₂‐water interfacial area which increases dissolution rates. We provide a conservative, first‐principles analysis of the quantity of CO₂ dissolved and the rate at which free‐phase CO₂ propagates in layered reservoirs. At early times, advection dominates the propagation of CO₂. This transitions to diffusion dominated propagation as the interfacial area increases and diffusive loss slows propagation. As surrounding water‐filled layers become CO₂ saturated, propagation becomes advection dominated. For reservoirs with finely bedded strata, ∼10% of the injected CO₂ can dissolve in a year. The maximum fraction of CO₂ that dissolves is determined by the volumetric ratio of water in low permeability layers and CO₂ in high permeability layers.

中文翻译：

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非均质多孔介质中二氧化碳的溶解截留率

二氧化碳（CO ₂）在盐水层中的溶解速率是次要捕集机制中受约束最少的，可以提高地质碳储藏的长期安全性。注入到非均质盐储层中的CO ₂将优先沿着高渗透率层行进，从而增加了CO _2-水界面面积，从而增加了溶解速率。我们对溶解的CO ₂量和自由相CO ₂在层状油藏中的扩散速率进行了保守的第一性原理分析。在早期，对流主导着CO ₂的传播。随着界面面积的增加，这转变为以扩散为主的传播，而扩散损失使传播变慢。随着周围充水层的CO ₂饱和，传播成为对流为主。对于地层精细的储层，一年内可溶解约10％的注入CO ₂。溶解的CO ₂的最大比例由低渗透率层中水与高渗透率层中CO ₂的体积比决定。