Patent ID: 7518949

Claim:
A method for determining a shear wave velocity of a subterranean formation, the method comprising: (a) deploying a downhole tool in a borehole, the downhole tool including at least one acoustic transmitter located at a first longitudinal position in the borehole and at least one acoustic receiver located at a second longitudinal position in the borehole; (b) propagating an audible acoustic signal in the borehole using the acoustic transmitter; (c) simultaneously (i) receiving an audible acoustic waveform from the acoustic signal and (ii) measuring an ultrasonic standoff distance between an outer surface of the downhole tool and the subterranean formation at at least one of the acoustic receiver(s); (d) evaluating the standoff distance measured in (c) to indicate a presence of leaky shear wave arrivals in the waveform simultaneously received in (c); and (e) processing the leaky shear wave arrivals to determine the shear wave velocity of the subterranean formation when the standoff distance evaluated in (d) indicates the presence of leaky shear wave arrivals.