利用纳米透射X射线显微成像技术研究页岩有机孔三维结构特征

发布时间：2019-06-11 05:02

【摘要】：页岩纳米级孔隙的三维结构特征直接决定页岩气微观渗流机理,是完善页岩储层流动模型亟需解决的核心问题。本文以龙马溪组页岩有机孔样品(直径约7μm)为研究对象,分别利用同步辐射纳米CT和实验室纳米CT重建有机孔三维空间结构,针对两个装置获得的孔隙结构参数进行对比研究,结果表明:(1)龙马溪组页岩有机孔样品呈蜂窝状,孔隙度约60%,连通性较好;孔径分布呈双峰模式,集中于60~150nm和500~1400 nm;孔径大于500 nm的孔隙对样品的总孔隙度贡献较大。(2)同步辐射纳米CT与实验室纳米CT结果相较,孔隙度和孔隙总数两参数基本一致,喉道总数和喉道半径偏差较大;孔径分布和配位数分布规律虽然类似,但具体数值存在明显差异,值得进一步深入比较分析和研究。(3)纳米CT方法在页岩纳米孔隙三维结构表征方面存在阈值划分难度大与扫描视场过小的问题,可从切片重构算法、三维数据处理、表征单元体三方面进行改进。
[Abstract]:The three-dimensional structure characteristics of shale nano-pores directly determine the microscopic seepage mechanism of shale gas, and it is the core problem to be solved to perfect shale reservoir flow model. In this paper, the organic pore samples of Longmaxi formation shale (about 7 渭 m in diameter) were taken as the research object, and the three-dimensional spatial structure of organic pores was reconstructed by synchrotron radiation nano-CT and laboratory nano-CT, respectively. The pore structure parameters obtained by the two devices are compared and studied. The results show that: (1) the shale organic pore samples of Longmaxi formation are honeycomb, the porosity is about 60%, and the connectivity is good; The pore size distribution is bimodal, concentrated in 60~150nm and 500 鈮，

本文编号：2497027