Dispersion Analysis Of Split Flexural Waves

Abstract

In this paper we first present a technique for measuring dispersion curves from array data, that is both simple and efficient. We demonstrate its performance on both synthetic and field data. We then use the technique to compute dispersion curves for split flexural waves from cross-dipole data from the Powder River Basin in Wyoming. In this data set we consistently observe crossover of the fast and slow flexural waves, an indication of stress-induced anisotropy. Next, we demonstrate the effect that dispersion-curve crossover has on Alford rotation. Finally, we give a procedure for rapidly determining stress-induced anisotropy from crossed-dipole logs.