摘要
为研究贵州牛蹄塘组页岩气在高温高压下的吸附规律,利用高压气体等温吸附仪测定了50℃、60℃、80℃下CH_4、CO_2在页岩中的等温吸附线,采用符合吸附规律的吸附模型对等温吸附线进行拟合,并用平均相对误差评价拟合效果。研究表明:低压阶段,CH_4、CO_2等温吸附线呈阶段性递增,具有I型吸附曲线特征;通过分析具有物理意义模型拟合参数,揭示了页岩的吸附规律,饱和吸附量VL和微孔吸附量V0与温度呈负相关关系,与TOC含量呈正相关关系,吸附强度b值随温度升高而减小,其他拟合参数所反映的吸附规律存在一定的差异;对比评价了各模型的拟合效果,三参数模型拟合效果优于二参数模型,对CH_4拟合效果最优的是L-F模型,对CO_2拟合效果最优的是E-L模型。高压阶段,一元线性方程对CH_4、CO_2的拟合效果较好,CH_4、CO_2在页岩表面的吸附量与压力之间呈负相关关系。同时探讨了研究成果对页岩气开采及储量评估的重要影响,为页岩气开发提供理论依据。
In order to study the adsorption characteristics of shale gas at high temperature and high pressure in Niutitang formation of Guizhou,the adsorption isotherms of CH_4 and CO_2 in shale at 50 ℃,60 ℃ and 80 ℃ were measured by high-pressure gas isothermal adsorption apparatus,were fitted by the adsorption model which accords with the adsorption law,and the fitting effect was evaluated by average relative error.The results show that the adsorption temperature of CH_4 and CO_2 is increasing in stage,and it has the characteristics of type Ⅰ adsorption curve;by analyzing the physical meaning of the model fitting parameters,the adsorption characteristics,saturation adsorption capacity VL and microporous adsorption.The amount of V0 is negatively correlated with the temperature and positively correlated with the content of TOC,and the adsorption b value decreases with the increase of temperature,and the adsorption law reflected by the other fitting parameters is different;the fitting of each model is evaluated the effect of the threeparameter model is better than that of the two-parameter model,the best for the CH_4 fitting is the L-F model;the best effect of the CO_2 fitting is the E-L model.In the high pressure stage,the linear regression equation of CH_4 and CO_2 is good,and the adsorption capacity of CH_4 and CO_2 on the shale surface is negatively correlated with the pressure.At the same time,the important influence of research results onshale gas exploitation and reserve assessment is discussed,which provides the theoretical basis for shale gas development.
作者
刘尚平
李希建
尹鑫
张培
李维维
LIU Shangping1,2 , LI Xijian1,2 , YIN Xin1,2 , ZHANG Pei1,2 , LI Weiwei1,2(1. Mining College, Guizhou University, Guiyang 550025, China; 2. Institute of Gas Disaster Prevention and Coalbed Methane Development, Guizhou University, Guiyang 550025, Chin)
出处
《中国矿业》
北大核心
2018年第6期160-166,共7页
China Mining Magazine
基金
贵州省重大应用基础研究项目资助(编号:黔科合JZ字[2014]2005)
关键词
页岩气
高温高压
等温吸附线
吸附模型
模型优选
shalc gas
high temperature and high prcssurc
isod
crmal adsorpuon linc
adsorpuon model
model optimization
