Mandrel eccentricity effects on acoustic borehole‐guided waves

A new analytical solution for acoustic wave propagation in a borehole with an eccentric mandrel is used to compute wavenumbers and excitation vectors for several guided modes as a function of tool position. Parameters used in the examples are relevant for slow shear wave logging‐while‐drilling applications where a large steel mandrel is free to move laterally about the borehole during data acquisition. An interesting mode splitting phenomenon is featured.