Preliminary modeling of the long-term fate of CO2 following injection into deep geological formations
Preliminary modeling of the long-term fate of CO2 following injection into deep geological formations
复制标题
二氧化碳注入深层地质构造后长期命运的初步模拟
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
S. Hedges
中科院分区：
文献类型：
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作者：
B. Strazisar;Chen Zhu;S. Hedges
向深层盐水层注入二氧化碳是减少温室气体的一个潜在办法。然而，在这一选择在经济和社会上被接受之前，必须研究几个关键问题，如地下储存时间和注入的二氧化碳的命运。在目前的研究中，一个一维的反应质量传输模型被用来预测长期的化学行为的深层盐水含水层CO2注入后，远离注入现场和代表盆地规模的迁移和长期的命运。注入的CO2溶解到盐水中导致pH值急剧下降，因此，酸性盐水与含水层矿物发生强烈反应。我们的模型还预测了铝硅酸盐矿物的溶解与次生矿物的形成和碳酸盐矿物的沉淀和溶解，并与实验室规模的CO2岩心驱油实验是一致的。然而，反应前沿的程度和发展取决于所使用的反应速率。例如，我们的建模结果表明，碳的运输可以显着延迟相对于盐水本身的流动，和大量的注入CO2是固定的，因为矿物捕获。碳反应性运输的精确位置和模式对所使用的反应速率敏感，说明需要改进反应动力学的知识，特别是铝硅酸盐矿物的溶解和沉淀的原位速率，以评估深部地质地层中CO2的矿物捕集。
The injection of CO2 into deep saline aquifers is a potential option for greenhouse gas mitigation. However, several key issues, such as underground storage time and the fate of the injected CO2, must be studied before this option becomes economically and socially acceptable. In the current study, a one-dimensional reactive mass-transport model was used to predict the long-term chemical behavior of a deep saline aquifer following CO2 injection, far away from the injection site and representative of basin-scale migration and long-term fate. The dissolution of the injected CO2 into brine causes a sharp drop in pH, and consequently, the acidic brine aggressively reacts with aquifer minerals. Our model also predicts the dissolution of aluminosilicate minerals with the formation of secondary minerals and the precipitation and dissolution of carbonate minerals and is consistent with laboratory-scale CO2 core-flooding experiments. However, the extent and development of reaction fronts depend on the reaction rates used. For example, our modeling results indicate that the transport of carbon can be significantly retarded with respect to the flow of the brine itself, and a significant amount of injected CO2 is immobilized because of mineral trapping. The precise locations and patterns of the carbon reactive transport are sensitive to the reaction rates used, illustrating the need for improved knowledge of reaction kinetics, particularly the in-situ rates of dissolution and precipitation of aluminosilicate minerals, in evaluating mineral trapping of CO2 in deep geological formations.