Abstract: 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.

Key words: Longmaxi Formation shales, high temperature, acoustic property, dynamic elasticity parameters, effect