初始水化学组分对CO_2矿物储存影响分析  

The influence of initial water chemical concentrations on the mineral trapping of CO_2

作　　者：胡婷[1] 商松华 杨豪[1] 宫晓艳[1] 杨志杰[1] 赵宁宁[1] 田海龙[1] 许天福[1] 

机构地区：[1]吉林大学环境与资源学院,吉林长春130021

出　　处：《可再生能源》2016年第9期1375-1382,共8页Renewable Energy Resources

基　　金：中国地质调查局二氧化碳地质储存综合地质调查项目(121201012000150010);国家科技重大专项课题(2016ZX05016-005);"吉林大学创新创业训练计划"项目(2015640913)

摘　　要：矿物储存被认为是CO2地质储存过程中最安全、最理想的一种储存形式,但此种形式受到诸多因素的影响,储层中的初始水化学组分是其中之一。文章以鄂尔多斯盆地石千峰组地层为例,利用数值模拟方法,通过显著性和相关性分析,定量评价初始水化学组分对CO2矿物储存量的影响。研究结果表明:初始水中Ca2+的主要敏感矿物为赤铁矿、高岭石、钙蒙脱石、菱镁矿和铁白云石,且初始水中Ca2+浓度变化对储层水中Fe2+,Mg2+,HCO3-浓度影响较大,初始水中K+的主要敏感矿物为伊利石,初始水中Na+的主要敏感矿物为钙蒙脱石,铁白云石为石千峰组地层中主要的固碳矿物;时间尺度为1 000 a时,H+,K+,Al3+浓度的改变,对HCO3-,CO2矿物储存量无明显影响,而Na+,Ca2+,Mg2+浓度的升高,会促进系统中矿物之间的转化,降低HCO3-的浓度,增加CO2的矿物储存量,且Ca2+对矿物转化和CO2的矿物储存量的影响最为强烈,Na+其次,Mg2+影响最小。Mineral sequestration is one of the most important mechanisms for the CO2 geological storage. However,it can be affected by several factors, such as the initial water chemical concentrations that could be of crucial importance. Based on the data of water chemistry from the Shiqianfeng formation in the Ordos Basin,numerical simulations and correlatioh analysis were conducted to quantitatively evaluate the effects of initial water composition on the mineral trapping mechanism. The results indicate that the concentration of Ca^2＋ plays an important role during alterations of hematite, kaolinite,smectite-Ca,magnesite and ankerite,K^＋ influences the illite and Na ＋ influences the smectite-Ca. In addition,concentrations of Fe^2＋,Mg^2＋ and HCO3^- in the reservoir are affected by Ca^2＋. Ankerite is the main carbonate mineral fixing carbon in the Shiqianfeng formation. After 1000 years of injection,the amount of CO2 trapped by mineral is not influenced by H^＋ ,K^＋ and Al^3＋ concentrations. However, the amount of solid CO2 increases with the concentration of Na^＋, Ca^2＋ and Mg^2＋.This is because the presence of these ions can accelerate the alteration of minerals. Among these three ions, Ca^2＋ plays the most important role followed by Na^＋, and Mg^2＋ on the amount of sequestrated CO2.

关 键 词：CO2地质储存 初始水化学组分 敏感矿物 矿物储存 数值模拟 

分 类 号：TK521[动力工程及工程热物理—热能工程] P618.130.21[天文地球—矿床学]