Leaky modes and wave components of a fluid-filled borehole embedded in an elastic medium

摘要

Based on the analysis of the complex poles of the characteristic function of the borehole system on four major Riemann sheets corresponding to the leaky modes, the wave components, such as compressional head arrival, shear wave and Stoneley wave, are calculated. It is pointed out that the existing head wave theory which neglects the contribution of the leaky modes is not applicable to the wave component calculation of the formation of large Poisson ratio. An improved method is proposed to isolate and calculate the wave components effectively and accurately.