Abstract

Post–stack inversion transforms a single seismic data volume into acoustic impedance through integration of seismic data and wells data. Benefits of acoustic impedance obtained after inversion are well established for stratigraphic interpretation in comparison to conventional seismic data analysis. In this study, model-based post stack seismic inversion is carried out with a 3D seismic data for Miocene sand to derive absolute P-Impedance (Zp) volume to delineate extension of hydrocarbon bearing sand reservoir of study area. The methodology of inversion includes wavelet estimation, well to seismic tie, and generation of initial 3D geological model. On analysis of the P-impedance volume, it has been observed that the prospective hydrocarbon (HC) bearing sands can be correlated with low Zp (i.e. 6100-6500 m/s*g/cc) just below H2 horizon which showed the oil-bearing sand and validated by wells (W-01, W-02, W-06, W-07 & W-08). Additionally, significantly low Zp (i.e. 5000-5700 m/s*g/cc) were also observed around 20 ms below from the H1 horizon sand which could be correlated to the gas bearing extra sand and tested in wells W-09.