SHEAR WAVE VELOCITY DETERMINATION USING EVANESCENT SHEAR WAVE ARRIVALS

摘要

A method for determining a shear wave velocity of a subterranean formation from a leaky shear wave arrival is disclosed. Standoff measurements are utilized to indicate the presence of leaky shear wave arrivals in the received waveforms. In one exemplary embodiment, leaky shear waves are indicated when the measured standoff distance is less than a predetermined threshold. The invention may provide for a direct determination of shear wave velocity in acoustically slow formations, thereby potentially improving accuracy as compared to prior art estimation techniques. The invention may further provide for improved power efficiency.