Mineral Sequestration of Carbon Dixoide in a Sandstone-Shale System
Mineral Sequestration of Carbon Dixoide in a Sandstone-Shale System
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DOI：
10.1016/j.chemgeo.2004.12.015
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发表时间：
2004-07
期刊：
影响因子：
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通讯作者：
Tianfu Xu;J. Apps;K. Pruess
中科院分区：
文献类型：
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作者：
Tianfu Xu;J. Apps;K. Pruess
利用墨西哥湾沿岸沉积物中常见的水文地质性质和矿物成分，建立了层状砂岩-页岩序列中CO2注入的概念模型。利用反应流体流动和地化输运程序TOUGHREACT进行了数值模拟，分析了砂岩和页岩之间的传质和碳酸盐沉淀固定CO2的过程。结果表明，CO2主要集中在砂岩中。捕集CO2的主要矿物为片钠铝石和铁闪石。10万年后，捕集CO2矿物的能力达到介质的90公斤/立方米左右。捕集CO2的能力取决于原生矿物的组成。菱铁矿和铁白铁矿的沉淀需要Fe2+，主要由绿泥石提供，部分由赤铁矿溶解还原提供。片钠铝石的沉淀需要由低长石溶解提供Na+。因此，绿泥石和寡长石的初始丰度会影响CO2矿物的捕集能力。所需的固存时间取决于矿物溶解和沉淀的动力学速率。片钠铝石的反应动力学还不是很清楚，对沉淀率的敏感性进行了检测。CO2作为二次碳酸盐的加入降低了孔隙率。页岩内部化学成分的淋滤导致孔隙度略有增加。目前关于天然高压CO2气藏矿物学的有限信息也与我们的模拟大体一致。《数值实验》对砂页岩地球化学系统的动态演化有了详细的了解。
A conceptual model of CO2injection in bedded sandstone–shale sequences has been developed using hydrogeologic properties and mineral compositions commonly encountered in Gulf Coast sediments. Numerical simulations were performed with the reactive fluid flow and geochemical transport code TOUGHREACT to analyze mass transfer between sandstone and shale layers and CO2immobilization through carbonate precipitation. Results indicate that most CO2sequestration occurs in the sandstone. The major CO2trapping minerals are dawsonite and ankerite. The CO2mineral-trapping capacity after 100,000 years reaches about 90 kg/m3of the medium. The CO2trapping capacity depends on primary mineral composition. Precipitation of siderite and ankerite requires Fe+2supplied mainly by chlorite and some by hematite dissolution and reduction. Precipitation of dawsonite requires Na+provided by oligoclase dissolution. The initial abundance of chlorite and oligoclase therefore affects the CO2mineral-trapping capacity. The sequestration time required depends on the kinetic rate of mineral dissolution and precipitation. Dawsonite reaction kinetics is not well understood, and sensitivity regarding the precipitation rate was examined. The addition of CO2as secondary carbonates results in decreased porosity. The leaching of chemical constituents from the interior of the shale causes slightly increased porosity. The limited information currently available for the mineralogy of natural high-pressure CO2gas reservoirs is also generally consistent with our simulation. The “numerical experiments” give a detailed understanding of the dynamic evolution of a sandstone–shale geochemical system.