页岩气藏岩石孔隙分形特征  

Fractal characteristics of rock pores in shale gas reservoir

作　　者：赵千慧 李治平[2] 赖枫鹏[2] 杜洋[2] 

机构地区：[1]中国地质大学(北京)非常规天然气能源地质评价与开发工程北京市重点实验室,北京100083 [2]中国地质大学(北京)能源学院,北京100083

出　　处：《辽宁工程技术大学学报（自然科学版）》2016年第9期914-919,共6页Journal of Liaoning Technical University (Natural Science)

基　　金：国家科技重大专项课题(2011ZX05009-006)

摘　　要：针对页岩非均质性强,难以用普通方法描述页岩孔隙结构的问题.以美国Fort Worth盆地石炭系Barnett组页岩和四川盆地志留系龙马溪组页岩为研究对象,基于分形理论和方法,以压汞实验测试结果为基础,对页岩孔隙结构展开定量化研究,计算了不同孔隙的分形维值,通过压汞曲线特征和分形曲线特征探讨了页岩孔隙结构特征.研究结果表明:页岩孔隙在特定范围内具有特定的分形特征,分形维数能够反映页岩内部孔隙结构;两类页岩压汞曲线区别在于大孔和微裂缝的发育情况;由不同形态的压汞曲线算得的分形维数双对数曲线也具有不同形态,计算分形维数时需按照不同形态分段拟合.龙马溪组页岩和Barneett页岩相比,孔隙结构更加复杂.Due to the strong heterogeneity of shale, it is difficult to describe the problem of the pore structure of the shale with common method. Taking BFS and LFS as the research object, a quantitative study on the pore structure of shale is carried out, and the fractal dimension of different pore space is calculated based on the fractal theory and the experimental results of mercury intrusion. The characteristics of pore structure are discussed by means of pressure mercury curve and fractal curve. The results illustrate that the porosity of the shale has specific fractal characteristics, and the fractal dimension can reflect the internal pore structure of the shale. The difference between the two types of shale pressure mercury curve lies in the development of large pores and micro cracks. The fractal dimension calculated by different forms of mercury curve is also different. The fractal dimension is calculated according to the different shapes of the fitting. As a result, the pore structure of BFS is more complicated than that of LFS.

关 键 词：Barnett页岩 龙马溪组页岩 孔隙结构 压汞测试 分形维数 毛管力曲线 裂缝发育 线性拟合 

分 类 号：TE329[石油与天然气工程—油气田开发工程]