Geochemical impact of CO2 and H2 injection on geomechanical and petrophysical properties of caprock to ensure safe containment: an experimental and an

CO2和H2储存开发商有道德、社会和法律的责任，以确保在地质时间尺度上的安全遏制。关键的安全和可预测的长期储存的CO2和H2的地质介质，是需要了解盖层的行为在存在潜在的反应性流体。将CO2和H2注入盐水层和/或耗尽的油气藏中储存将改变原位地球化学环境，可能导致与盖层的反应。反过来，这可能会改变盖层的地质力学和岩石物理特性，可能会增加从主储层中迁移出来的风险。耦合地球化学和地质力学效应的盖层在CO2或H2的存在下，了解甚少，研究不足，尽管岩石强度和密封能力的关键控制。通过研究这两个学科之间的相互作用，可以限制对岩石强度控制器和后续泄漏途径的新理解，帮助降低未来CCUS和潜在H2储存项目的风险。这一开创性的实验研究将直接揭示地球化学效应对典型储层条件下盖层关键地质力学性质的影响。如何测量的强度，渗透率，弹性和声学特性，和反应表面积的盖层的注入流体的存在下的影响将提供基本的约束盖层的完整性CO2和H2注入网站。这项工作将能够识别CO2和H2注入关键盖层属性之间独特的地球化学和地质力学差异，首次进行同类比较研究，通过提供盖层长期稳定性的区分和排名标准来帮助未来的选址。

CO2 and H2 storage developers have a moral, social, and legal responsibility to ensure safe containment over geological time scales. Critical to safe and predictable long-term storage of CO2 and H2 within geological media, is the need to understand caprock behaviour in the presence of potentially reactive fluids. Injection of CO2 and H2 for storage into saline aquifers and/or depleted hydrocarbon reservoirs will alter the in-situ geochemical environment, potentially leading to reactions with the caprock. This, in turn, may alter the geomechanical and petrophysical properties of the caprock, possibly increasing the risk of migration out of the host reservoir. The coupled geochemical and geomechanical effects on caprocks in the presence CO2 or H2 are poorly understood and under-researched despite being key controls on rock strength and sealing capacity. By investigating the interplay between these two disciplines, a new understanding on controllers of rock strength and subsequent leakage pathways can be constrained, helping de-risk future CCUS and potential H2 storage projects. This pioneering experimental study will directly reveal the geochemical effects on key geomechanical properties of caprocks under representative reservoir conditions. Measurements of how the strength, permeability, elastic and acoustic properties, and reactive surface area of caprocks are affected by the presence of injected fluids will provide fundamental constraints on caprock integrity for CO2 and H2 injection sites. This work will enable identification of the unique geochemical and geomechanical differences between CO2 and H2 injection upon key caprock properties, the first comparison study of its kind, aiding future site selection by providing criteria to differentiate and rank sites by the long-term stability of the caprock.