Abstract

This study presents an integrated rock physics and petrophysical workflow aimed at improving compressional velocity (Vp), shear velocity (Vs) and density (RHOB) modelling and lithofacies discrimination in a complex carbonate reservoir setting of the field-X in mumbai offshore. Recognizing the limitations of conventional constant-m models in capturing the diverse pore systems typical of carbonates, a core-calibrated variable cementation exponent (m) was adopted. The m-values, derived from core measurements and validated through sonic-to-total porosity log relationships, reflect variations due to vuggy, moldic, and fracture porosity systems. The incorporation of variable m significantly enhanced the prediction accuracy of elastic properties—Vp, Vs and RHOB—by aligning modelled values more closely with measured data. Furthermore, the improved water saturation estimates directly impacted the quality of facies classification and seismic inversion results, aiding in the delineation of reservoir heterogeneity. This workflow, combining petrophysical calibration, log-derived porosity partitioning, and rock physics modelling (Xu-Payne framework), offers a robust and scalable approach for elastic property prediction and seismic-reservoir integration in carbonate settings.