枯竭油藏CO_2地质封存对地表变形的影响

The Influence of Geological Storage of Carbon Dioxide on Deformation of Ground Surface in Depleted Reservoirs

二氧化碳封存技术可以有效解决当前碳排放过量的问题,但是其注入地层后与地层发生相互作用引发地层变形,会对生态环境造成一定的影响。为了探究CO_2注入对地表变形的具体影响,基于渗流-应力耦合理论,通过数值模拟,研究了二氧化碳封存对地表变形的影响,得到了二氧化碳注入速度、注入压力和原始地层压力对地表变形的影响规律,结果表明:地表变形与注入速度和注入压力为正相关关系,与原始地层压力为负相关。研究可为降低CO_2地质封存过程中的地质灾害风险提供理论参考。

CO2 geological storage is an efficient way to reduce the carbon emission. However, the deformation and movement of ground surface were induced by the interaction of fluid and layers after injection, which may have influence on ecological environment and cause geological disasters. In order to find a thorough inquiry into the relationship between surface deformation and CO2 injection, numerical simulation about CO2 injection with three factors, that is, injection rate, injection pressure and initial pore pressure, based on hydro-mechanics coupling method, was conducted. The results show that the vertical displacement of ground surface increases with the increase of injection rate and injection pressure, but reduces with the increase of initial pore pressure. This study may give a theoretical reference for reducing geological disasters induced by CO2 geological storage.