Carbon dioxide flow behaviour in macro-scale bituminous coal: An experimental determination of the influence of effective stress
Carbon dioxide flow behaviour in macro-scale bituminous coal: An experimental determination of the influence of effective stress
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DOI：
10.1016/j.energy.2023.126754
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发表时间：
2023-04
期刊：
影响因子：
9
通讯作者：
Xiao-guang Zhang;Chaoyang Jin;Decheng Zhang;Chengpeng Zhang;P. Ranjith;Yong-qian Yuan
中科院分区：
文献类型：
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作者：
Xiao-guang Zhang;Chaoyang Jin;Decheng Zhang;Chengpeng Zhang;P. Ranjith;Yong-qian Yuan
煤中CO2流动行为的实验研究一般是在细观尺度(长度小于100 mm)的样品上进行的，结果不适用于更大的尺度。在本研究中，在宏观尺度重组高煤阶煤样(直径203 mm，长1米)上进行了CO2流动特性的实验测试。记录了渗透率值、压力发展剖面、样品的体积应变和CO2储存特征，并进行了比较，以解释结果。观察到CO2渗透率随注入压力的增加而降低，特别是在超临界CO2注入时，但在较高的CO2注入压力下，减少率较低。随着深度的增加，CO2渗透率降低，注水压力越高，降低幅度越大。保持相对较高的CO2注入压力会在煤中产生更大的压力发展，有效影响区(CO2压力可能至少保持注入压力的90%的区域)随着深度的增加而减小，但在一定程度上随注入压力的增加而增加。CO2储存量随深度的增加而减小，在CO2注入初期，注入压力越低，CO2注入速率越大。然而，对于每一次喷射，最终的CO2储存容量都随着CO2喷射压力的增加而增加。
Experimental studies on CO2flow behaviour in coal are generally performed on meso-scale specimens (less than 100 mm in length), the results are not applicable at a larger scale. In this study, CO2flow behaviours were experimentally tested on macro-scale reconstituted high rank coal samples (203 mm in diameter and 1 m in length). The permeability values, pressure development profiles, volumetric strains of the sample and the CO2storage characteristics were recorded and compared to interpret the results. It was observed that CO2permeability reduces with injection pressure, especially for supercritical CO2injections but lower reduction rates were observed at higher CO2injection pressures. With the increase of depth, CO2permeability reduces and this reduction is greater for higher injection pressures. Maintaining a relatively high CO2injection pressure creates greater pressure development in coal, and the effective zone of influence (areas where the CO2pressure may remain at least 90% of the injection pressure) decreases with depth but increases with injection pressure to some extent. CO2storage capacity reduces with depth, and the CO2injection rate is greater for lower injection pressures during early stages of CO2injection. However, the ultimate CO2storage capacity increases with CO2injection pressure for each injection.