Carbonate reservoirs has formed most of the hydrocarbon reservoirs worldwide. Rock physics models as a practical tool by considering different geological parameters and creating a relationship between them provide special templates to characterize these reservoirs. Present study aims to determine the type of lithofacies using empirical models and rock physics templates. The study was performed in one of Iran’s southwest oil fields in a well with a reservoir thickness of almost 100 meters with carbonate lithology. In two separate sections, lithologies were evaluated using radioactive data and compressive and shear velocities and comparison with the empirical model. The results were compared and it was found that even though the formation had a small amount of shale, calcite and dolomite formed the major lithology of the reservoir zone of interest.