Experimental investigation on anisotropic permeability and its relationship with anisotropic thermal cracking of oil shale under high temperature and triaxial stress
Experimental investigation on anisotropic permeability and its relationship with anisotropic thermal cracking of oil shale under high temperature and triaxial stress
复制标题
高温三轴应力下油页岩各向异性渗透率及其与各向异性热裂化关系的实验研究
DOI：
10.1016/j.applthermaleng.2018.10.005
复制
发表时间：
2019
影响因子：
6.4
通讯作者：
Huang Xudong
中科院分区：
文献类型：
--
作者：
Wang Guoying;Yang Dong;Zhao Yangsheng;Kang Zhiqin;Zhao Jing;Huang Xudong
利用高温三轴渗透试验机模拟现场条件，研究了油页岩在应力作用下的渗透率各向异性。垂直于层理方向的渗透门槛温度为450 °C，平行于层理方向的渗透门槛温度为400 °C。垂直层理的渗透率在450 °C以下小于10 - 20 m2，在450-600 °C时从10 - 19 m2增加到10 - 17 m2。平行层理的渗透率在400 °C以下为10 - 19 ~ 10 - 18 m2，在400 ~ 600 °C时从10 - 16 ~ 10 - 15 m2增加。平行层理渗透率与垂直层理渗透率之比在450 °C时最大。同时，通过X射线计算机断层扫描对样品的微观结构进行了表征。热裂缝主要发生在顺层方向，垂直于顺层方向的裂缝很少。温度升高引起的热裂缝是平行于层理方向渗透率变化的主要原因，大孔隙连通是垂直于层理方向渗透率变化的主要原因。
A high-temperature triaxial permeability testing machine was used to study anisotropic permeability of oil shale at stresses that emulatein-situconditions. The threshold temperature of permeability in the direction perpendicular to bedding is 450 °C and in the direction parallel to bedding is 400 °C. The magnitude of permeability of perpendicular bedding is low than 10−20m2below 450 °C, and increase from 10−19to 10−17m2at 450–600 °C. The magnitude of permeability of parallel bedding is 10−19to 10−18m2below 400 °C, and increase form 10−16to 10−15m2at 400 to 600 °C. The ratio of permeability of parallel bedding to permeability of perpendicular bedding was maximal at 450 °C. Simultaneously, sample microstructure was characterized by X-ray computed tomography. Thermal cracks mainly occur in the bedding direction, and cracks perpendicular to the bedding are rare. Thermal cracks caused by increased temperature are the main reason for the change of permeability in the direction parallel to bedding, and the connection of macropores is the main reason for the change of permeability in the direction perpendicular to bedding.