NUMERICAL INVESTIGATION ON THE PROPAGATION OF ELASTIC WAVES IN A BOREHOLE

In this paper, the numerical analysis of elastic waves propagatingalong a fluid-filled borehole excited by a point acoustic source is inves-tigated. It is shown that the propagating traces of compressional and shearwaves proposed in the dynamic model are in agreement with the onesobtained in the geometrical acoustic theory. It is also shown that theshear waves are affected by the compressional and Pseudo-Rayleigh waves.The amplitudes of Stoneley waves are not affected by the pincipal frequencyof transmission from the source. Compressional waves, shear waves andPseudo-Rayleigh waves of multiple modes are affected by the source principal frequency, and indicate that they have characteristic propagatingfrequencies. No direct fluid wave exists.