The possibility of leakage of CO2 from a geological storage reservoir is of serious concern to stakeholders. In this work, high–pressure-temperature laboratory experiments were performed to demonstrate the application of a silicone membrane-sensor system in the monitoring of subsurface gases, especially in the leakage scenario. Mass permeation, membrane resistance to gas permeation, and the gas flux across the membrane are reported for two gases, namely, CO2 and N2. Mass permeation of CO2 through the membrane was more than ten times higher than that of N2, under similar conditions. It was also found to increase with the geological depths. The gas flux remains higher for CO2 as compared to N2. From the results, a simple criterion for distinguishing the presence of the different gases at various geological depths was formulated based on the rate of permeation of gas through the membrane. Results and techniques in this work can be employed in the detection/monitoring of subsurface gas transport, especially in geological carbon sequestration.

中文翻译：

---

多孔介质中超临界 CO2 和 N2 硅膜的渗透性、选择性和鉴别标准

CO2 从地质储存库泄漏的可能性是利益相关者严重关注的问题。在这项工作中，进行了高压温度实验室实验，以证明有机硅膜传感器系统在监测地下气体中的应用，特别是在泄漏情况下。对两种气体，即 CO2 和 N2，报告了质量渗透、膜对气体渗透的阻力和穿过膜的气体通量。在类似条件下，CO2 通过膜的质量渗透比 N2 高十倍以上。还发现它随着地质深度的增加而增加。与 N2 相比，CO2 的气体通量仍然较高。从结果来看，根据气体通过膜的渗透率，制定了一个简单的标准，用于区分不同地质深度处不同气体的存在。这项工作的结果和技术可用于检测/监测地下气体运输，尤其是地质碳封存。