Acoustic field in a borehole within fluid formations with a horizontal interface (Q1276636)

We study an acoustic field in a cylindrical borehole embedded in a horizontally layered infinite medium. The modes in each layer are found to consist of continuous and discrete modes, and we prove the orthogonality and completeness of these modes. The relevant weights associated with the two kinds of modes are determined by solving a set of integral equations derived from the boundary conditions at the layer interface. We evaluate reflection, transmission and coupling coefficients of different modes, and verify the numerical results by comparison with the method of real axis integration, with a hybrid method, and with scaled laboratory experiments.