基于纳米CT及数字岩心的页岩孔隙微观结构及分布特征研究Research on Microstructure of Shale Pores and Distribution Features Based on Nano-CT Scanning and Digital Core Analysis
郭雪晶,何顺利,陈胜,陈玺,王烁,秦玲玲
摘要(Abstract):
通过对四川盆地龙马溪组页岩样品进行纳米CT扫描及三维数字岩心分析,对样品内黄铁矿、有机质及孔隙进行了三维重构。在此基础上,分析了岩石组分的空间展布和孔隙结构特征,探讨了孔隙的连通性,并获得了孔隙数量及体积差分分布曲线。研究表明:1当前尺度内,岩石各组分如黄铁矿、有机质等的分布呈现非均质性,孔隙分布也具有微观非均质性;2孔隙多分布在有机质内以及不同矿物之间,孔隙大小从纳米级到微米级,孔隙形状从近球形到复杂多边形均有呈现,以不规则椭球形为最多见;3孤立孔隙占有较大的比例,而流动通道的形成主要依赖大孔隙的相互连接;4孔隙数量分布呈幂律分布,即随着孔隙半径减小,孔隙数量按幂级数规律增长;孔隙体积在log(R)=2.0左右达到波峰,在log(R)高于2.350时,孔隙体积分布趋于平稳,可以通过体积差分分布曲线覆盖面积大小来直观比较不同取值范围内的孔隙总体积大小。
关键词(KeyWords): 页岩样品;纳米CT;数字岩心;孔隙结构;孔隙分布
基金项目(Foundation):
作者(Author): 郭雪晶,何顺利,陈胜,陈玺,王烁,秦玲玲
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