热流固耦合作用下注采参数对CO2驱替瓦斯影响规律研究OA
Influence of injection-production parameters on CO2 displacement of gas under thermal-hydraulic-mechanical coupling
注入CO2驱替瓦斯是提高深部低渗透煤层瓦斯抽采效率的关键手段,同时能实现CO2地质封存,兼具经济与环境效益.为了探究CO2注入煤层驱替瓦斯的规律,提出了一种考虑二元气体渗透、扩散、竞争吸附及煤体变形的热流固耦合模型,借助COMSOL数值模拟软件,系统研究了不同注气压力、注采间距下CO2浓度、煤体渗透率及温度的动态变化,分析了不同注采参数下的CH4采收率、CO2封存量,以评估驱替效果.研究结果表明:①注气压力、注采间距的增大可显著提高CO2在煤体中的扩散能力,加剧煤体变形,使渗透率与温度波动更明显.②注气压力从0.5 MPa增加至2.5 MPa,注气60 d后CH4采收率、CO2封存量分别提高了10.47％,387.00％,CO2封存量对注气压力的变化更敏感.③ 注采间距从3 m增大至7 m时,注气60 d后CH4采收率、CO2封存量分别提高了48.34％,9.19％,CH4采收率对注采间距的变化更敏感.④工程应结合实际目标优化注采参数,若以瓦斯增产为主,应优先增大注采间距;若以CO2封存为主,应优先增大注气压力.现场工艺试验进一步证实,增大注气压力与注采间距可有效提高瓦斯抽采速度和产量,验证了热流固耦合模型的可靠性.
Injection of CO2 to displace gas is a key method to improve gas extraction efficiency in deep low-permeability coal seams,and can also realize CO2 geological storage,delivering both economic and environmental benefits.To investigate the laws of CO2 injection into coal seams for gas displacement,a thermal-hydraulic-mechanical coupling model considering binary gas seepage,diffusion,competitive adsorption,and coal deformation was proposed.With COMSOL numerical simulation software,dynamic changes in CO2 concentration,coal permeability,and temperature under different gas injection pressures and injection-production spacings were systematically studied,and CH4 recovery rate and CO2 storage amount under different injection-production parameters were analyzed to evaluate the displacement effect.The results showed that:① increases in gas injection pressure and injection-production spacing could significantly improve the diffusion capacity of CO2 in coal,intensify coal deformation,and make fluctuations in permeability and temperature more obvious.② When gas injection pressure increased from 0.5 MPa to 2.5 MPa,CH4 recovery rate and CO2 storage amount after 60 d of injection increased by 10.47％and 387.00％,respectively,and CO2 storage amount was more sensitive to changes in gas injection pressure.③ When injection-production spacing increased from 3 m to 7 m,CH4 recovery rate and CO2 storage amount after 60 d of injection increased by 48.34％and 9.19％,respectively,and CH4 recovery rate was more sensitive to changes in injection-production spacing.④ Engineering applications should optimize injection-production parameters according to actual objectives.If gas production enhancement was the main goal,injection-production spacing should be increased preferentially.If CO2 storage was the main goal,gas injection pressure should be increased preferentially.Field process tests further confirmed that increasing gas injection pressure and injection-production spacing could effectively improve gas extraction rate and yield,verifying the reliability of the thermal-hydraulic-mechanical coupling model.
朱由创;张黎明;田小强;杨秀福
贵州盘江精煤股份有限公司土城矿,贵州 盘州 553529贵州大学 矿业学院,贵州 贵阳 550025贵州盘江精煤股份有限公司土城矿,贵州 盘州 553529瓮福(集团)有限责任公司,贵州贵阳 550002
矿业与冶金
热流固耦合模型CO2驱替瓦斯注气压力注采间距煤体渗透率
thermal-hydraulic-mechanical coupling modelCO2 displacement of gasgas injection pressureinjection-production spacingcoal permeability
《工矿自动化》 2026 (5)
176-184,9
国家自然科学基金项目(52174072).
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