高温影响下页岩岩石的声学特性实验研究

以四川盆地龙马溪组页岩为研究对象，研究了高温处理后页岩岩样物理性质的变化规律，讨论了温度对页岩岩石声波特性的影响，同时，也研究了高温影响下页岩岩石动弹性参数的变化规律。研究结果表明，当作用温度低于400℃时，温度对页岩表观颜色和物理性质影响较小，而当作用温度超过400℃时，页岩表观颜色逐渐由黑色变为灰白色，且页岩质量下降快、体积膨胀率上升快，造成页岩密度下降快；随着温度增加，页岩声波速度不断下降，且声波主频不断下降，而页岩声波衰减系数不断增大，且声波衰减系数对页岩热损伤效应的敏感性更强；随着温度增加，页岩损伤因子增大，同时，页岩动态泊松比也呈增大趋势，而页岩动态弹性模量、体积模量、剪切模量呈下降趋势。

An Experiment Study on the Effect of High Temperature on the Acoustic Properties of the Shale

Taking the organic shale of Longmaxi Formation in Sichuan Basin as the research object, the variation laws of physical properties of shale rock samples after high temperature treatment are investigated. The influences of high temperature on the acoustic characteristics of shale rocks are discussed. And the variation laws of dynamic elastic parameters of shale rocks under high temperature influence are also studied. The results show that when the operating temperature is lower than 400℃, the temperature has little effect on the apparent color and physical properties of the shale, but when the operating temperature exceeds 400℃, the apparent color of the shale gradually changes from black to grayish white, and the shale quality declines rapidly, the volume expansion rate rises rapidly, the shale density decreases rapidly. As the temperature increases, the shale acoustic wave velocity decreases continuously, and the acoustic wave dominant frequency decreases, while the shale acoustic wave attenuation coefficient increases continuously, and the acoustic wave attenuation coefficient is more sensitive to the thermal damage effect of shale rock than the acoustic wave velocity. As the temperature increases, the shale damage factor increases, and the dynamic Poisson's ratio of shale also increases, while the dynamic elastic modulus, bulk modulus and shear modulus of shale rock samples decrease.