中文摘要：

为了研究页岩吸附甲烷的机理,通过容积法测定35,50和65℃时页岩甲烷吸附等温线,计算甲烷在页岩上的等量吸附热和极限吸附热,从热力学角度分析甲烷在页岩上的吸附行为。研究结果表明：甲烷在页岩上的吸附等温线具有Ⅰ型等温线特征,Langmuir吸附模型较好地拟合了吸附数据;根据吸附等温线计算的等量吸附热为15.50~17.65 kJ/mol,平均为16.88 kJ/mol,说明页岩对甲烷的吸附为物理吸附;等量吸附热随甲烷吸附量的变化而变化,是页岩表面的不均匀性和吸附分子间作用力综合作用的结果;极限吸附热定量地反映了页岩表面与甲烷气体作用力;在页岩气藏开发时,除了采用降压解吸开采外,对于极限吸附热较大的页岩气藏,可通过注入吸附能力更强的CO2等促使甲烷解吸。

英文摘要：

In order to investigate the mechanism of methane adsorption on shales, black shale samples were performed for adsorption experiments, and adsorption isotherms of methane on shales at 35, 50 and 65 ℃ were measured. The isosteric heat and limit isosteric heat of methane adsorption on shale were also calculated to study the thermodynamics behavior. The results show that adsorption isotherms of methane in shale are typeⅠ isotherms, and Langmuir adsorption model fits the adsorption data well. The isosteric adsorption heat calculated from the adsorption isotherms is from 15.50 to 17.65 kJ/mol with an average of 16.88 kJ/mol, which indicates that the dominant adsorption performance may be physical adsorption. The isosteric heat of methane adsorption on shale changes with the increase of volume adsorbed, which is caused by the combination of energetically heterogeneous surface and intermolecular forces of methane. The limit isosteric heat reflects quantitatively the intermolecular forces between methane and shale. During the development of shale gas reservoir, CO2 with higher adsorption capacity can be injected into the high limit isosteric heat reservoir to enhance methane recovery.