Currently, there are concerns about the safety of carbon sequestration in the geological media. To assuage this concern, scientists and engineers have the tasks to demonstrate fool-proof and comprehensive techniques that can monitor the movement, or otherwise, concentration of the injected CO₂ in the subsurface. In this work, well-defined laboratory experiments were used to demonstrate the key physico-chemical characteristics and dielectric parameters that are useful in monitoring carbon sequestration sites. The porous materials used were basalt and silica sand samples to demonstrate the possibility of CO₂ injection into different media. To simulate the resident fluids, distilled and brine water samples were used in separate experimentations. Also, the pressures and temperatures were chosen to correspond to different geological depths which are relevant for CO₂ injection. The pH, bulk electrical conductivity (${\sigma }_{\mathrm{b}}$) and bulk dielectric permittivity (${\epsilon }_{\mathrm{b}}$) of the system were measured for the two different media. On one hand, the decrease in pH was clearly observed in both the basalt and silica sand after the exposure to CO₂. On the other hand, ${\sigma }_{\mathrm{b}}$ and ${\epsilon }_{\mathrm{b}}$ increased as CO₂ was injected. Our results further revealed a higher ion mobilisation​ potential in basalt medium than that in silica sand. This results in lower pH and higher electrical conductivity in the basalt medium than the silica medium. Thus, a simultaneous measurement of pH, ${\sigma }_{\mathrm{b}}$ and ${\epsilon }_{\mathrm{b}}$ are proposed as a multiparameter approach to monitor CO₂ leakage from the storage reservoir. As far as we are aware, this is the first work in the open literature that reports simultaneous dielectric and electrical behaviours of CO₂ –water–porous media system for basalt porous medium in connection with carbon sequestration.

当前，对地质介质中固碳的安全性存在担忧。为了缓解这种担忧，科学家和工程师的任务是演示防呆和全面的技术，该技术可监视地下CO ₂的运动或浓度。在这项工作中，使用定义明确的实验室实验来证明关键的理化特性和介电参数，这些参数可用于监测碳固存位点。所使用的多孔材料是玄武岩和硅砂样品，以证明存在CO ₂的可能性注入不同的媒体。为了模拟驻留流体，在单独的实验中使用了蒸馏水和盐水样品。同样，选择压力和温度以对应于与CO ₂注入相关的不同地质深度。pH，总电导率（${\sigma }_{\mathrm{b}}$）和体积介电常数（${\epsilon }_{\mathrm{b}}$）分别针对两种不同的媒体进行了测量。一方面，在暴露于CO ₂之后，在玄武岩和硅砂中都清楚地观察到pH的降低。另一方面，${\sigma }_{\mathrm{b}}$ 和 ${\epsilon }_{\mathrm{b}}$随着注入CO ₂增加。我们的结果进一步表明，玄武岩介质中的离子迁移潜力高于硅砂中的离子迁移潜力。与二氧化硅介质相比，玄武岩介质中的pH值较低，电导率较高。因此，同时测量pH${\sigma }_{\mathrm{b}}$ 和 ${\epsilon }_{\mathrm{b}}$提出了一种多参数方法来监视CO ₂从存储容器泄漏的情况。据我们所知，这是公开文献中的第一篇工作，该论文报道了玄武岩多孔介质的CO _2-水-多孔介质系统与碳固存同时发生的介电和电学行为。