COMPRESSIONAL AND SHEAR WAVES IN A FLUID-FILLED BOREHOLE

Theoretical analysis shows that there exist singular points in the branch cut solution expressions of the compressional and shear waves, corresponding to the special solutions in the branch points given by Yu, i.e., resonance modes. We analysed the full acoustic wave trains in a laboratory borehole model and found that the amplitutes of the compressional and shear waves are less than the values calculated by the branch cut solutions, which indicated that the branch cut solutions can not be used to explain the compressional and shear waves. The results of the spectra analysis of the compressional and shear waves from the full wave trains have good agreement with these from experiment and resonance modes.