CO₂ convective mixing in saline aquifers has been widely studied numerically and experimentally. Reservoir heterogeneity is significant for CO₂ convective mixing and experimental studies are still limited. In this study, we have conducted a visualization of CO₂ convective mixing experiments in heterogeneous porous media at reservoir conditions using CO₂ and water. We have used a two‐dimension Hele–Shaw cell, different glass beads of different permeability at porous media, and water solution with pH indicator. Glass beads were packed in a different way (horizontally and vertically) to generate the heterogeneity inside the test cell. We have studied transport velocity deviation due to the heterogeneity and effects of permeability transition zone together with the effects of boundary conditions. It was found out that having a low permeable layer below a high permeable layer restructure the flow of CO₂ fingers and dampens the CO₂ transport velocity. With the vertical permeability zones, having a high permeability zone accelerates CO₂ gravity transport through that zone which is a good representation for a fracture or a fault in the reservoir. CO₂ convection onset is governed by the vertical high‐permeable layer. Boundary conditions have been dominant with the presence of high permeable zones. It also found out that the experimental results presented in this study match with the simulation studies that are available in the literature. © 2021 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons Ltd.

中文翻译：

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储层温度和压力条件下非均质多孔介质中CO2溶解和对流的可视化研究

在盐水层中CO ₂对流混合已经进行了广泛的数值和实验研究。储层非均质性对于CO ₂对流混合很重要，并且实验研究仍然很有限。在这项研究中，我们使用CO ₂对储层条件下非均质多孔介质中CO ₂对流混合实验进行了可视化和水。我们使用了二维的Hele-Shaw池，在多孔介质上具有不同渗透率的不同玻璃珠以及带有pH指示剂的水溶液。玻璃珠以不同的方式（水平和垂直）包装，以在测试单元内部产生异质性。我们研究了由于渗透率过渡带的非均质性和边界条件的影响而引起的运输速度偏差。已发现在高渗透层之下具有低渗透层可重新构造CO ₂指状物的流动并抑制CO ₂输送速度。对于垂直渗透区，高渗透区会加速CO _2的排放重力通过该区域传输，很好地表示了储层中的裂缝或断层。CO ₂对流的开始取决于垂直的高渗透层。高渗透区的存在一直是边界条件的主导。还发现，本研究中提供的实验结果与文献中提供的模拟研究相符。©2021作者。温室气体：化学工业协会和约翰·威利父子有限公司出版的科学技术。