地下深部封存CO2已经被公认是人类削减温室气体排放的一条有效而又科学的途径。深部咸含水层CO2地质封存因封存潜力巨大,技术可行,且已有实际的工程运行,因而备受关注。松辽盆地是中国潜在的CO2储存场地之一,选择松辽盆地为大尺度模拟研究对象,选取姚家组砂岩层为储层,选取嫩江组泥岩为盖层,运用TOUGH-MP并行计算代码建立了覆盖整个松辽盆地的三维地质模型,在中央凹陷区开展大尺度CO2注入模拟研究,包括CO2运移、储存、地层压力提升以及储存安全性等问题。模拟结果表明:持续注入100a后形成的CO2羽远小于产生的压力积聚区影响范围。注入产生的压力抬升将在注入停止后迅速消散,不会对区域地层压力和浅层地下水系统产生显著影响。在千年之内注入的CO2将随着时间持续,逐渐溶解于水中,而不会因盖层微弱的渗透性而逃逸。
Carbon dioxide (CO2) geological disposal into saline aquifers is a promising approach to control the emission of greenhouse gases due to its huge potential in storage capacity and feasibility in technology. Songliao Basin, a large continental sedimentary basin in northeastern China, is one of the great potential candidate sites for future CO2 storage in China. In this study, a 3D regional-scale CO2 storage model was developed to evaluate the CO2 plume evolution and pressure build-up of large-scale CO2 injection into the saline aquifers in the Center Depression of the Songliao Basin. COz was injected into the Yaojia Formation through ten wells with annual total rate of 10 Mt over 100 years. To solve the large-scale model efficiently, a parallel multiphase flow simulator, TOUGH2-MP/ECO2N, was adopted for the simulation. Simulation results suggest that propagation of pressure is far reaching and large covering of the model domain is necessary, even though the CO2 plume is much smaller. The pressure change is sensitive to the injection amount and permeability of the confined layers. The simulation results demonstrate that even the permeability of caprocks of the storage system is not fully impermeable, injected CO2 cannot escape from the site in several thousand years.