f Temperature Dependence of Ultrasonic Velocities in Shales – Can We Use It For Interpreting Time-lapse Seismic?

The temperature dependence of ultrasonic velocities in shales show significantly larger temperature sensitivities than predicted by the Gassmann fluid-substitution model, which can be attributed to temperature dependent velocity dispersion. We expect the temperature dependence of velocities to be frequency dependent, resulting in different temperature sensitivities at seismic, sonic and ultrasonic frequencies.