For our mathematical model we consider a right circular cylinder or borehole filled with fluid and surrounded by a homogeneous isotropic, elastic solid—the formation. An infinitesimally thin line source is located in the fluid parallel to the borehole axis and very close to the borehole wall. The formation compressional and shear velocities are both faster than the fluid velocity. We calculate the early time response for different angles between source and receiver. This is done with great accuracy using the first terms of the ray expansion. The arrival structure apparent in the synthetic waveforms is explained. The propagation characteristics of the circumferential creeping waves are derived from the dispersion curves for the corresponding traveling wave representation. Our results show that for most fast formations, typical borehole sizes, and transmitter-receiver spacings between 60° and 120°, circumferential formation dominated arrivals can be separated from fluid dominated modes provided the center frequency of the signal is sufficiently high. The model for the no loss case predicts that only the circumferential compressional and pseudo-Rayleigh waves are detectable and that the circumferential shear wave is highly attenuated.