黔北牛蹄塘组页岩CO_(2)与甲烷吸附特性研究  

Research on the Adsorption Characteristics of the Niutitang Shale Formation in Northern Guizhou for CO_(2) and CH_(4)

作　　者：张瑞嘉 李波波[1] 吕心妍 孙龙委 陈希庆 ZHANG Ruijia;LI Bobo;LYU Xinyan;SUN Longwei;CHEN Xiqing(School of Mining,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学矿业学院,贵州贵阳550025

出　　处：《贵州大学学报(自然科学版)》2025年第2期116-124,共9页Journal of Guizhou University:Natural Sciences

基　　金：国家自然科学基金资助项目(52274183);贵州省基础研究(自然科学)资助项目(黔科合基础-ZK[2021]重点052,黔科合平台人才-YQK[2023]013)。

摘　　要：为研究深部页岩气开采与CO_(2)封存过程中页岩吸附特性,利用高精度高压气体等温吸附仪,选取中国黔北牛蹄塘组页岩开展了高温高压条件下不同吸附性气体(CH_(4),CO_(2))的等温吸附试验,基于试验结果建立了考虑不同孔隙吸附机制差异的超临界等温吸附模型,通过试验数据验证了模型的可靠性与合理性。研究结果表明,随气体压力升高,CH_(4)、CO_(2)过剩吸附量均呈先增加后逐渐减小的趋势。同一温度下,各个压力点下CH_(4)、CO_(2)气体过剩吸附量的大小关系均为CO_(2)>CH_(4);CO_(2)气体吸附能力显著高于CH_(4)气体。此外,随温度升高在各个压力点下页岩对CH_(4)、CO_(2)气体的吸附量均减小。超临界状态下,常规Langmuir模型拟合精度较差,所得等温吸附曲线与试验现象不符。改进的DR-L模型可以更好地表征超临界状态下页岩吸附特性。在各深度条件下页岩CO_(2)含气量均高于CH_(4),与页岩对CH_(4)、CO_(2)气体吸附能力大小关系一致。研究结果为进一步揭示二氧化碳地质封存机理提供理论依据,助力碳达峰碳中和目标如期实现。To investigate the shale adsorption characteristics during deep shale gas exploitation and CO_(2) storage,a highprecision high-pressure gas isothermal adsorption instrument was used.Shale from the Niutitang Formation in northern Guizhou was selected to conduct isothermal adsorption experiments for different adsorptive gases(CH_(4),CO_(2))under high temperature and high pressure conditions.Based on the test results,a supercritical isothermal adsorption model considering the differences in adsorption mechanisms of different pores was established.The reliability and rationality of the model were verified by experimental data.The results show that as the gas pressure increases,the excess adsorption amounts of CH_(4) and CO_(2) both show a trend of first increasing and then gradually decreasing.At the same temperature,the relationship between the excess adsorption amounts of CH_(4) and CO_(2) gases at each pressure point is CO_(2)>CH_(4);the gas adsorption capacity of CO_(2) is significantly higher than that of CH_(4) gas.In addition,as the temperature increases,the adsorption amounts of shale on CH_(4) and CO_(2) gases at each pressure point decrease.In the supercritical state,the fitting accuracy of the conventional Langmuir model is poor,and the obtained isothermal adsorption curve is inconsistent with the experimental phenomenon.The improved DRL model can better characterize the shale adsorption characteristics in the supercritical state.Under various depth conditions,the shale CO_(2) gas content is higher than that of CH_(4),which is consistent with the relationship between the adsorption capacities of shale on CH_(4) and CO_(2) gases.The research results provide a theoretical basis for further revealing the mechanism of geological storage of carbon dioxide and facilitate achieving the goals of carbon peaking and carbon neutrality as scheduled.

关 键 词：CO_(2)地质封存 超临界吸附 高温高压 吸附模型 CH_(4)置换 页岩气采出 

分 类 号：TE122.1[石油与天然气工程—油气勘探]