Abstract

Reservoir characterization of gas-bearing sands in the Lower Goru Formation of the Jaisalmer Sub-basin presents significant challenges due to pronounced lateral heterogeneity, which limits the effectiveness of traditional seismic interpretation methods. Conventional post-stack attributes and pre-stack inversion techniques have demonstrated limited success in discriminating against gas reservoirs from surrounding facies. Rock Physics Modelling (RPM) conducted on data from eight wells revealed that gas sands exhibit distinguishable characteristics in the Vp/Vs domain. However, reliable volumetric estimation of Vp/Vs ratios was hindered by the poor fidelity of the seismic data. To overcome these limitations, this study introduces Fluid Impedance (FI) as a robust and innovative alternative for gas reservoir characterization. The FI method demonstrated superior performance in isolating gas-bearing facies, with anomalies that align consistently with well data from known gas zones. This approach offers significant advancement for exploration workflows, providing reliable discrimination between reservoir and non-reservoir facies in complex geological settings where traditional methods fail. The method effectively identified gas anomalies in Lower Goru formation across multiple wells validating the testing results