摘要
为了对页岩孔隙结构特征进行更加精细地评价,需要对页岩孔的低温氮吸附试验数据进行综合分析。运用分形理论,分析了不同孔类型表面积分形维数Db和体积分形维数Dt特征,对比了分形维数与孔隙结构特征参数之间的相关关系。结果表明：半封闭型墨水瓶状孔（具有Ⅰ类吸附回线）的Dt大于2.8,四周开口型平行板状孔（Ⅲ类）Dt为2.6-2.8,四周开口型尖劈状孔（Ⅱ类）Dt为2.2-2.6;Db和Dt分别与平均孔径、BET比表面积、BJH总孔体积、有机碳含量TOC和类镜质组反射率Ro具有明显相关性。页岩孔隙分形特征显示,Db和Dt分别指示了孔隙内表面和空间形态的复杂程度,可用来定量表征页岩储层微孔结构及地球化学特征。
In order to more finely evaluate the porous structure features of the shale,a comprehensive analysis should be conducted on the data of the low temperature nitrogen absorption experiment. A fractal theory was applied to analyze the features of the different pore type surface fractal dimension Db and the volume fractal dimension Dt and to compare the correlation relationship between the fractal dimension and the porous structure feature parameters.The results showed that the Dt value of an＂ink-bottle＂type half closed pore（ with Type I adsorption loop） was over 2.8,the Dt value of a periphery open pore type parallel plate pore（ Type Ⅲ） was ranging from 2.6 - 2.8 and Dt value of a periphery open type spire pore（ Type Ⅱ） was 2.2 - 2.6.The Db and Dt individually had obvious correlation relationship with the average pore size,BET specific surface,BJH total pore volume,organic carbon content TOC and vitrinite reflectance Ro.The porous fractal features of the shale showed that the Db and Dt individually could indicate the complexity of the pore internal surface and space form could be applied to quantitatively express the micropore structure and the geochemical features of the shale reservoirs.
出处
《煤炭科学技术》
CAS
北大核心
2016年第9期167-171,177,共6页
Coal Science and Technology
基金
国家自然科学基金资助项目(41272176)
高等学校博士学科点专项科研基金资助项目(20110022110007)
关键词
页岩气
低温氮吸附试验
分形维数
湘西北
孔隙结构
shale gas
low temperature nitrogen absorption experiment
fractal dimension
Northwest Hunan
porous structure
