A Novel Experimental Study on Density‐Driven Instability and Convective Dissolution in Porous Media
A Novel Experimental Study on Density‐Driven Instability and Convective Dissolution in Porous Media
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DOI：
10.1029/2021gl095619
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发表时间：
2021-11
影响因子：
5.2
通讯作者：
R. Guo;Hanxing Sun;Qingqi Zhao;Zihao Li;Yang Liu;Cheng Chen
中科院分区：
文献类型：
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作者：
R. Guo;Hanxing Sun;Qingqi Zhao;Zihao Li;Yang Liu;Cheng Chen
深部咸水层中的地质二氧化碳（CO₂）封存（GCS）是缓解人为二氧化碳排放对全球气候变化影响的一种有前景的解决方案。溶解在地层水中的二氧化碳会增加溶液密度，并可能导致可混溶的密度驱动的向下对流，这显著加速了注入二氧化碳的溶解捕集。关于可混溶的密度驱动对流的实验研究很有限。在实验室中，我们发现反射绿光强度与溶质浓度之间存在经验线性相关性，这使得能够在时空域内对溶质浓度进行原位测量，进而测量穿过多孔介质顶部边界的质量通量。利用这些新的实验技术，我们确定了密度驱动不稳定性和对流溶解开始的临界瑞利 - 达西数以及临界时间尺度。这是首次通过实验室实验确定这些关键系统参数的研究。
Geological carbon dioxide (CO2) sequestration (GCS) in deep saline aquifers is a promising solution to mitigate the impact of anthropogenic CO2 emissions on global climate change. CO2 dissolved in formation water increases the solution density and can lead to miscible density‐driven downward convection, which significantly accelerates the dissolution trapping of injected CO2. Experimental studies on miscible density‐driven convection have been limited. In the laboratory, we found an empirical linear correlation between reflected green light intensity and solute concentration, which enabled in situ measurements of solute concentrations in the spatial and temporal domains and consequently the mass flux across the top boundary of the porous medium. Using the novel experimental techniques, we determined the critical Rayleigh‐Darcy number and critical time scales for the onset of density‐driven instability and convective dissolution. This is the first study to determine these critical system parameters using laboratory experiments.