Simulation of Wave Propagation In A Thermoelastic Media Adopting The L-S Theory Under The Seismic Frequency Band

Exploration of geothermal resources is important from the energy point of view. As one of the key geophysical exploration methods, classical seismic-wave propagation theory regards the underground medium as completely elastic under isothermal or adiabatic deformation. However, the underground medium is not completely elastic under the influence of temperature. Therefore, studying the propagation process of the thermoelastic wave is of great significance to geothermal exploration. The problem of wave propagation in thermoelastic media can be described based on the L-S theory, considering the effect of temperature on wave propagation. This is important for adopting seismic exploration methods to find geothermal fields. Based on previous research, we realize the numerical simulation of wave propagation in thermoelastic media by adopting staggered-grid and PML absorption boundary and propose an absorption method for the reflection on temperature boundary. Then, the propagation process of thermoelastic waves under the condition of constant temperature and the variable temperature was compared. It is observed that with the increase of reference temperature, the amplitude of the E-wave becomes larger, and the wave velocity becomes faster. The new wavefield simulation method can effectively synthesize seismic records for following inversion work. This method lays a foundation for thermoelastic wave imaging and inversion.