岩盐沉淀对咸水层二氧化碳地质封存注入过程的影响:以江汉盆地为例

依托江汉盆地基础地质和水文地质数据,通过建立新沟嘴组一维、二维径向数值模型,对该储层进行CO2封存注入数值模拟研究,分析二氧化碳注入储层后,咸水层中发生的地球物理化学作用.以CO2的溶解作用和岩盐的沉淀作用为主,分析它们对储层压力和注入性的影响.模拟结果表明,二氧化碳注入储层后,近井周围会形成3个分区,即纯液相区、两相混相区、盐沉淀区；盐沉淀会导致压力积累严重,影响CO2可注入性；对盐度的敏感性分析表明,咸水含水层盐度越大,压力积累会越严重.因此,江汉盆地CO2地质封存应考虑盐度的影响,采取相关缓解压力积累的措施.

Impact of Halite Precipitation on CO2 Injection into Saline Aquifers: A Case Study of Jianghan Basin

In this paper,we set up one-dimensional and two-dimensional radial models to do researches on CO2 geological storage,based on the geological and hydrogeological data in Jianghan Basin.Our researches mainly focus on CO2 dissolution and halite precipitation to analyse the impacts on reservoir pressure and injectivity of CO2.The simulation results show that,after CO2 injection,there will form three regions near the injection well,including the dry-out region,two-phase region and the liquid-phase region.Solid precipitation in the dry-out region would induce pressure buildup,and then affect the injectivity of CO2.We also carry out sensitivity analysis on precipitation.The results reveal that as the salinity of the saline aquifer increases,the solid precipitation would increase and pressure buildup would be more severe.Hence CO2 geological storage in Jianghan Basin should consider the salinity impacts and there is a need to take some measures to alleviate pressure buildup.