The velocity of compressional and shear waves is of great importance in geomechanical and petrophysical studies. Often due to the high cost and operational constraints, shear wave velocity is not available in all wells, especially older wells. Therefore, considering the applications and importance of shear wave in studies of hydrocarbon reservoirs, the researchers attempted to establish relationships to estimate shear wave velocity using compressional wave velocity. In this study, we first obtain the compressional wave velocity through the sonic log of two wells in Whicher-Range field, Western Australia. Afterwards, we estimate the shear wave velocity using empirical equations from the compressional wave velocity. Vp/Vs ratio was calculated to recognize lithology and reservoir fluids. Using the results obtained from the experimental relationships together with two wells from the studied field and one seismic section, seismic inversion is performed. The results indicate the presence of a gas bearing hydrocarbon reservoir in the Sue Formation.