油气地质与采收率2026，Vol.33Issue(1)：26-38,13.DOI:10.13673/j.pgre.202509028
干酪根中页岩气吸附-解吸滞后机理及其影响因素分析
Mechanism of adsorption-desorption hysteresis of shale gas in kerogen and influencing factors analysis
摘要
Abstract
The adsorption behavior of methane in kerogen is of great significance for shale gas reserve evaluation and production prediction.However,there is still a lack of clear understanding of the hysteresis phenomenon and its micro-causes in the process of methane desorption.Therefore,based on the real kerogen model,the grand canonical Monte Carlo and molecular dynamics(GCMC-MD)coupling method was used to systematically investigate the adsorption-desorption behavior of methane under different conditions and the pore structure evolution characteristics of kerogen.The results show that the volumetric strain of kerogen shows a continuous growth during the methane adsorption process.This positive feedback mechanism of"adsorption,expansion,and readsorption"effectively expands the available pore space and significantly improves the methane storage capacity of the kerogen.Under the same pressure conditions,the methane's absolute adsorption amount in the depressurization stage is higher than that in the pressurization stage,thus showing a significant hysteresis loop on the isothermal adsorption-desorption curve.The fundamental mechanism is that the kerogen skeleton undergoes partial irreversible structural deformation,making the thermodynamic path of the adsorption-desorption process do not coincide.The increase of temperature will weaken the interaction between methane molecules and pore wall,reduce the adsorption capacity,and alleviate the hysteresis in the desorption process.Under high temperature conditions,the overall deformation response ability of kerogen decreases.Compared with the type III-A kerogen,the type II-A kerogen has a higher proportion of micropores,which leads to a higher energy barrier to methane in the desorption process,thus aggravating the difficulty of desorption.关键词
干酪根/甲烷吸附/滞后机理/孔隙变形/分子模拟Key words
kerogen/methane adsorption/hysteresis mechanism/pore deformation/molecular simulation分类
能源科技引用本文复制引用
唐海俊,邱星栋,刘逸盛,戴霞,唐聪,黄亮,王磊..干酪根中页岩气吸附-解吸滞后机理及其影响因素分析[J].油气地质与采收率,2026,33(1):26-38,13.基金项目
国家自然科学基金青年基金项目"基于原位表征的多尺度孔缝空间页岩油相态特征研究"(52304022),四川省科技厅自然科学基金青年基金项目"四川盆地侏罗系陆相页岩油气孔-缝耦合尺度相变规律及其理论模型构建"(2025ZNSFSC1354),四川省科技厅自然科学基金面上基金项目"CO2吞吐提高页岩油采收率过程中助溶剂微观致效机理"(2024NSFSC0201). （52304022）
