A study of caprock hydromechanical changes associated with CO2-injection into a brine formation
A study of caprock hydromechanical changes associated with CO2-injection into a brine formation
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DOI：
10.1007/s00254-001-0499-2
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发表时间：
2002-06-01
期刊：
影响因子：
--
通讯作者：
Tsang, CF
中科院分区：
文献类型：
--
作者：
Rutqvist, J;Tsang, CF
对假设的盐水含水层/盖层系统深部注入超临界CO2时的流体力学变化进行了数值研究。采用新开发的计算机模型对注入过程进行了模拟，该模型用于对二氧化碳和盐水流动进行多相分析，同时考虑了传热和岩石变形。在这个模型中，二氧化碳在10年的时间里以恒定的速率注入1300 - 1500英尺的深度。注入带上覆盖着一层100米厚的盖层，位于1200 - 1300英寸，在研究的一个案例中，该盖层被一条垂直断层相交。研究了注入引起的液压响应、机械响应和流体力学响应。这包括CO2羽流的扩散、有效应力变化、地表隆起、应力诱导的渗透率变化和机械失效分析。分析表明，尽管注入压力接近地层应力值，但大部分流体力学变化发生在靠近注入带的盖层下部，而上部的密封机制可能保持完整。
A numerical study of hydromechanical changes during a deep underground injection of supercritical CO2 in a hypothetical brine aquifer/caprock system is conducted. The injection process is simulated using a newly developed computer model for multi-phase analysis Of CO2 and brine water flow, coupled with heat transfer and rock deformations. In this modeling, CO2 is injected at a constant rate over a 10-year period at a depth of 1,300-1,500 in. The injection zone is overlain by a 100-m-thick caprock, located at 1,200-1,300 in, which in one of the studied cases is intersected by a vertical fault. The hydraulic, mechanical as well as hydromechanical responses caused by the injection are studied. This includes the spread of the CO2 plume, effective stress changes, ground surface uplift, stress-induced permeability changes, and mechanical failure analysis. The analysis shows that most hydromechanical changes are induced in the lower part of the caprock near its contact with the injection zone, whereas the sealing mechanism of the upper part may remain intact, despite an injection pressure close to the lithostratic stress value.