Experimental Investigation on Composition and Pore Structure Evolution of Organic-Rich Shale via Supercritical Water
Experimental Investigation on Composition and Pore Structure Evolution of Organic-Rich Shale via Supercritical Water
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DOI：
10.1021/acs.energyfuels.3c02416
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发表时间：
2023-09
期刊：
影响因子：
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通讯作者：
Fanyi Meng;Chuanjin Yao;Xinge Du;Tianyuan Di;Hexing Zhang;Jiao Ge
中科院分区：
文献类型：
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作者：
Fanyi Meng;Chuanjin Yao;Xinge Du;Tianyuan Di;Hexing Zhang;Jiao Ge
在富含有机质页岩的原位转化过程中，页岩成分和内部孔隙结构的演化不仅直接关系到页岩的传热传质过程，而且影响着热解产物在页岩孔隙中的流动和运移。本研究比较了高温高压氮气和超临界水对页岩热解过程的影响。结果表明，页岩在氮气中的比表面积低于在超临界水中的比表面积。超临界水作为热解介质，更有利于页岩孔隙的发育。随着超临界水温的升高，微孔与中孔的比例发生变化，导致平均孔径显著增大。页岩内部孔隙的扩张和有效孔隙的发育有利于页岩内部形成更多的渗流通道，从而增加页岩基质的连通性。此外，页岩在超临界水中的孔隙度从室温的7.0182%增加到450C时的53.1124%，孔隙度增加了7.6倍，表明超临界水温可以控制页岩孔隙度的变化。这些现象突出了超临界水在页岩原位转化中的应用潜力。
In in situ transformation of organic-rich shale, the evolution of shale composition and internal pore structure not only is directly related to the heat and mass transfer process but also affects the flow and migration of pyrolysis products in shale pores. In this study, the influence of high-temperature and high-pressure N2and supercritical water on shale pyrolysis process was compared. The results illustrated that the specific surface area of a shale under N2was lower than that under supercritical water. As a pyrolysis medium, supercritical water is more favorable to the development of pores in a shale. As the supercritical water temperature increased, the ratio of the micropores to mesoporous pores changed, leading to a significant increase in the average pore size. The expansion of the pores inside a shale and the development of effective pores are conducive to the formation of more seepage channels inside the shale, thus increasing the connectivity of the shale matrix. In addition, the porosity of the shale under supercritical water increased from 7.0182% at room temperature to 53.1124% at 450 °C, and the porosity increased by 7.6 times, which indicated that the supercritical water temperature could control the change of shale porosity. These phenomena highlight the potential of supercritical water application in in situ shale transformation.