Ali Ranjbar

Shear wave velocity is considered as one of the most important physical parameters of rock, which can be measured with dipole sonic imager (DSI) logging tool. On the other hand, these data are not available in all wells, and therefore, the accurate and reliable estimation of this parameter with the least uncertainty in determining the characteristics of the reservoir is of great importance. The shear wave speed prediction approach in this study includes two impirical methods and a rock physic models. In experimental methods, empirical correlations reported in studies have been used. In the second method, two rock physics models, Gaussmann and Xu and Payne, which are more complicated than the experimental models, have been chosen to determine the characteristics of the shear wave velocity. In this study, all the stated methods are compared based on the correlation coefficient (R2) and Average Relative Error (ARE). The final results showed that the Greenberg and Castagna method with Gaussmann fluid replacement theory leads to more uniform performance and better prediction of shear wave velocity with accuracy of R2=0.9067.