中文摘要：

CO2咸水层封存被广泛认为是一种具有大规模温室气体减排潜力的地学前缘技术。选取中国第一个全流程CCS项目为研究背景,结合工程实际情况,选取鄂尔多斯盆地为具体研究对象,提取相关参数,建立相应的地质模型,通过数值模拟研究咸水层多层统注时CO2在咸水中的主要封存机制、CO2在地层中的运移分布特征及其与注入能力的关系,并观测由于CO2注入引起的地层压力、CO2摩尔分数、酸碱度等的变化情况,为方案的进一步优化奠定基础。研究表明,CO2注入咸水层后,大部分进入储层上部,且注入能力越大时,注入的层位越多,注入量越大;CO2在咸水层中的存在形式有自由态、束缚态和溶解态。所有探索性研究的目的是给示范性项目的未来提供一个良好的基础优化方案。

英文摘要：

Geological storage of carbon dioxide （CO2） into deep saline aquifers is a leading-edge technology of greenhouse gas emissions reduction. The paper investigates China＆#39;s first full-chain carbon capture and storage （CCS） project, i.e. Shenhua CCS demonstration project. Combining actual operation condition, the site of demonstration project in Ordos Basin is selected for the study. The relevant parameters are extracted to establish the geological model that is used to simulate multilayer injection of CO2 into deep saline aquifers. In order to analyze migration and distribution of CO2 while and after injection, the relationship between injection capacity and storage mechanisms of CO2 is investigated in detail. Additionally, it is also investigated on changes of formation pressure, CO2 phase, CO2 mole fraction and pH value. The numerical simulation shows that when CO2 is injected into deep saline aquifers, it is almost sequestered into the top of the reservoir. When the injection capacity is stronger, CO2 is injected into more layer formations, and the injection volume of CO2 is relatively bigger. The injected CO2 bears a very complicated phase state in deep saline aquifers. It is mixed with a free gas, trapped and dissolved phases. Simultaneously, when an injection rate is different, main phase types of injected CO2 into deep saline aquifers are different and they change with time. The change pattern of pH values is also different because of strength of seepage effect caused by different injection rates. All exploratory studies are aiming at building a good foundation to optimize future schemes of the demonstration project.