基于TOUGHREACT-MP的苏北盆地盐城组咸水层CO_2矿物封存数值模拟  

Numerical Modeling of CO_2 Sequestration in the Saline Aquifer of Yancheng Formation in Subei Basin Using TOUGHREACT-MP

作　　者：莫绍星 龙星皎 李瀛[1] 郑菲[1] 施小清[1] 张可霓[2] 赵良[1] 

机构地区：[1]表生地球化学教育部重点实验室/南京大学地球科学与工程学院,南京210023 [2]北京师范大学水科学研究院,北京100875

出　　处：《吉林大学学报（地球科学版）》2014年第5期1647-1658,共12页Journal of Jilin University：Earth Science Edition

基　　金：江苏省自然科学基金项目(BK2012313);国家大学生创新训练计划项目(G1210284016);江苏省产学研联合创新资金计划项目(BY2010136)

摘　　要：基于TOUGHREACT并行版,建立了苏北盆地盐城组下段砂岩层在碳封存中的CO2-水-岩反应二维径向模型,并评估储层的矿物封存潜力,探讨分析了网格剖分精度和储层各向异性对矿物封存模拟的影响。模拟结果表明:在CO2封存过程中,片钠铝石、方解石和菱铁矿沉淀较明显,在CO2注入5 000a后矿物封存的比例高达34.0%;网格剖分精度的不同对矿物封存反应路径没有影响,但粗网格模型计算得到的矿物封存量偏高;降低储层的kv(垂向渗透率)在短期内会促进CO2的水平运移,有利于溶解和矿物封存;但随着时间延长,降低kv对对流作用的抑制开始体现,表现为1 000a后中等kv值的模型计算出的矿物封存量高于较大kv和较小kv值的模型。The two-dimensional radial model of CO2-water-rock reaction in carbon sequestration of Yancheng Group under section sandstone layer in Subei basin is built based on TOUGHREACT parallel version.The mineral sequestration potential in reservoir is evaluated.The influence of grid subdivision precision and anisotropy of reservoir on mineral sequestration simulations is analyzed.The simulation results show that dawsonite,calcite and siderite,significantly precipitated in the process of CO2 sequestration.The total mass of CO2 sequestrated by mineral trapping is as high as 34.0%after 5 000 a.The grid resolution has little impact on the reaction path of minerals sequestration,however,the total amount of CO2 mineral sequestration with coarser grid is overestimated comparing to that with finer grid.The discretion of the vertical permeability（kv）would lead to a more rapid horizontal migration of injected CO2 to the middle and bottom,which results in an incretion in solubility trapping and mineral trapping for a short period of time.However,for a long term,with the increasing instability of the system due to CO2 dissolution,the vertical convective mixing becomes significant,it turns out to be a significant inhibition of convection by decreasing kv.It shows that the mineral sequestration calculated by middle kvvalue model is higher than the larger kvand smaller kvvalue model after 1 000 a.

关 键 词：CO2的矿物封存 网格剖分精度 各向异性 苏北盆地 

分 类 号：P641.69[天文地球—地质矿产勘探]