摘要
页岩孔隙结构在页岩储层研究中占有十分重要的地位。为了查明页岩热致孔隙结构演化特征,文中以鄂尔多斯盆地长7段页岩为例,基于加热到不同温度并冷却的页岩样品,利用扫描电镜对其进行微观结构扫描,并利用颗粒(孔隙)及裂隙图像识别与分析系统(PCAS)对扫描电镜照片中的孔隙进行定量表征。结果表明:不同温度下,样品以大孔和裂隙为主,孔径多小于20μm,占比80.30%~90.89%,其中大孔占比50.72%~64.91%;随着温度的增加,样品中孔隙-裂隙整体面积增大,微裂隙逐渐发育,孔隙形状因子随着温度升高而逐渐增大,孔隙边缘粗糙且形状更为复杂,孔隙逐渐过渡为裂隙;孔隙-裂隙发育方向在370℃时存在拐点,370℃前孔隙-裂隙发育方向随机性逐渐增大,370℃后发育方向逐渐均一。
The pore structure of shale plays an important role in the study of shale reservoirs.In order to find out the evolution characteristics of shale thermal-induced pore structure,the shale of Chang 7 Member in Ordos Basin is taken as an example.Based on the shale samples heated to different temperatures and then cooled,the microscopic structure was scanned by scanning electron microscope,and the pores in the SEM photos were quantitatively characterized in combination with the image recognition and analysis system of particles(pores)and fractures(PCAS).The results show that at different temperatures,the samples are dominated by macropores and fractures.The pore diameters are mostly less than 20μm,accounting for 80.30%-90.89%,and the macropores account for 50.72%-64.91%.With the increase of temperature,the whole area of pores and fractures increases,microfractures develop gradually,pore shape factor increases gradually with the increase of temperature,pore edges are rough and more complex,and pores gradually transition to fractures.There is an inflection point at 370℃in the development direction of pore-fracture,the randomness of pore-fracture development direction increases gradually before 370℃,and the development direction becomes uniform after 370℃.
作者
肖斌
郭东旭
赵忠英
李胜
XIAO Bin;GUO Dongxu;ZHAO Zhongying;LI Sheng(College of Mining,Liaoning Technical University,Fuxin 123000,China;Research Institute of Exploration and Development,PetroChina,Beijing 100083,China;Liaoning Geology Engineering Vocational College,Dandong 118000,China)
出处
《断块油气田》
北大核心
2025年第5期746-753,共8页
Fault-Block Oil & Gas Field
基金
国家自然科学基金项目“深部煤层可控冲击波致裂强化瓦斯抽采多相多场跨尺度耦合机制研究”(52174117)
辽宁省自然科学基金项目“阜新盆地煤系泥页岩微纳米孔缝系统特征”(2022-BS-328)。
关键词
孔隙-裂隙结构
形状因子
分形维数
温度
定量表征
页岩
pore-fracture structure
shape factor
fractal dimension
temperature
quantitative characterization
shale
作者简介
第一作者:肖斌,男,1988年生,博士,主要从事页岩气地质方面的研究。E-mail:binxiao2013@126.com;通信作者:郭东旭,男,1999年生,硕士,主要从事页岩气地质方面的研究。E-mail:2608934696@qq.com。
