CO_2地质封存室内实验中盐水种类对残余水形成的影响  

The effects of brine species on the formation of residual water in laboratory experiments of CO_2 geological storage

作　　者：李铱 李旭峰[2] 沈照理[1] 于青春[1] 

机构地区：[1]中国地质大学(北京)水资源与环境学院,北京100083 [2]中国地质调查局水文地质环境地质调查中心,河北保定071051

出　　处：《地学前缘》2015年第4期312-319,共8页Earth Science Frontiers

基　　金：国土资源部公益性行业科研专项"深部咸水层二氧化碳地质储存关键技术研究(低渗;超低渗储集岩参数测试与物理模拟技术方法研究)"(201211063-04)

摘　　要：在咸水含水层中进行CO2地质封存是通过向含水层中注入CO2驱走咸水实现的。在大部分地下水被驱走之后,仍会有部分地下水残留在原来的岩石孔隙中形成残余水。残余水的形成过程及残余水饱和度的大小对CO2地质封存潜力及地质封存安全性等都具有重要影响。本研究通过超临界CO2排驱饱水岩心实验,研究了盐水种类对残余水的形成过程及残余水饱和度大小的控制作用。实验结果表明,在盐水浓度相同(35g/L)的情况下,超临界CO2排驱盐水的最终稳定不可再降的残余水饱和度是去离子水<NaCl盐水<CaCl2盐水。从实验结果看,超临界CO2排驱咸水的过程可划分为3个阶段,本文分别称他们为活塞式排驱阶段、携带式排驱阶段和溶解式排驱阶段。论文提出了一个毛细管模型,利用这一模型对这3个阶段中CO2排驱水的机理进行了分析。CO2 geological storage in deep saline aquifers was achieved by injecting CO2 into the aquifers and displacing the brine. Although most of the groundwater was displaced, some residual groundwater remained in the rock pore. The formation process of residual water and the irreducible water saturation both have important impacts on the potential and security of CO2 geological storage. We studied the effects of brine species on the formation of residual water and the irreducible water saturations through the experiments of super-critical COe displaced saturated rock core. Results show that the ranking of the irreducible water saturations in a same concentration of 35 g/L are Deionized Water〈NaC1 Brine〈CaC12 Brine. The process of drainage can be divided into three stages according to the experimental results： the Piston Drainage, Portable Drainage and Dissolved Drainage stages. This paper proposed a capillary model that is used to interpret the mechanism of COe drainage.

关 键 词：CO2地质封存 超临界CO2 残余水饱和度 毛细管模型 排驱过程的3个阶段 

分 类 号：P641[天文地球—地质矿产勘探] X143[天文地球—地质学]