高温对富有机质页岩岩石物理特性的影响

High temperature effects on rock physical properties of organic-rich shale

熊健 林海宇 刘向君 梁利喜 黄宏 李贤胜

XIONG Jian LIN Haiyu LIU Xiangjun LIANG Lixi HUANG Hong LI Xiansheng

1. 油气藏地质及开发工程国家重点实验室(西南石油大学), 成都 610500; 2. 中国石油集团 测井有限公司 西南分公司, 重庆 400021

1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China; 2. Southwest Branch, CNPC Logging Company Limited, Chongqing 400021, China

以四川盆地下志留统龙马溪组富有机质页岩为研究对象，分析了高温处理后页岩岩石物理特性的变化规律，同时也探讨了高温对页岩岩石力学特性的影响。研究结果表明，随着温度的升高，页岩岩样的色调逐渐由黑色变为灰白色；页岩样品质量随着温度增加先缓慢下降后再快速下降，而孔隙度和渗透率先缓慢上升后快速上升，即质量、孔隙度和渗透率在温度增加的过程中发生了较明显变化，说明该过程中存在一个阈值温度，龙马溪组页岩的阈值温度范围在300~400℃；随着温度的增加，页岩样品纵横波时差降低，而纵横波衰减系数增大；随着温度增加，页岩样品单轴抗压强度降低，弹性模量下降，泊松比变化规律不明显。

The Longmaxi Formation shale in the Sichuan Basin was used to study the changing physical properties of shale after high temperature treatment and the influences of high temperature on the rock mechanical properties of shale. As the temperature increases, the color of shale specimens gradually changes from black to gray. The quality of shale samples decrease slowly first and then rapidly with the increase of temperature, but the porosity and permeability increase slowly at first and then rapidly. The significant changes in quality, porosity and permeability indicate that there is a threshold temperature in this process, and the threshold temperature of the Longmaxi Formation shale range from 300 to 400℃. With the increase of temperature, the acoustic time difference of longitudinal wave and shear wave decreases, while the attenuation coefficient of longitudinal and shear wave increases. With the increase of temperature, the uniaxial compressive strength and the elastic modulus of shale samples decrease, while changes in Poisson's ratio are not obvious.

国家自然科学基金项目"水岩作用对硬脆性页岩孔隙结构及声波特性影响的研究"（41872167）资助。

https://doi.org/10.11781/sysydz201906910