Abstract

This study delivers an integrated assessment of the CO₂ sequestration potential of the Deccan Trap basalts in the Saurashtra Offshore Basin through a robust static modelling workflow. The methodology combines regional site screening, advanced petrophysical and geomechanical analysis, seismic inversion, facies classification, and machine learning-based property modelling. Well logs and 3D seismic data underpin highresolution structural and facies frameworks. Petrophysical results reveal promising porosity and permeability within fractured and vesicular basalt zones, while geomechanical evaluations confirm the sealing integrity of overlying caprocks for secure, long-term containment. Seismic inversion enhanced lithofacies prediction and porosity mapping, reducing subsurface uncertainty. Volumetric estimates indicate substantial storage capacity, with in-situ mineralisation facilitated by reactions with Ca-, Mg-, and Fe-rich silicates. Findings demonstrate that Deccan Trap basalts can serve as viable, reactive reservoirs for permanent CO₂ storage. This integrated workflow offers a replicable approach for appraising other basalt provinces, supporting India’s decarbonisation objectives.