Abstract

The Raghavapuram(RGP) Formation in the Krishna-Godavari (KG) Basin is a geologically significant stratigraphic unit, recognized for its dual role as a source rock and a reservoir for hydrocarbons. It is considered a major contributor to both oil and gas generation, particularly in the onland areas of the basin. Lenticular sand bodies within the Raghavapuram Shale believed to have formed during intervening regressive phases also present potential reservoir zones. However, correlating stratigraphic features within the formation poses substantial challenges due to its complex depositional patterns. To address this, the Relative Geological Time (RGT) model has been introduced as an effective tool for identifying structural and stratigraphic features, and it has proven valuable in reservoir characterization. Widely applied in seismic interpretation, RGT models assist geoscientists in understanding the temporal and spatial relationships between rock layers. Within the Raghavapuram Formation, the use of RGT modelling enhances the delineation of subtle stratigraphic variations and improves the identification of prospective hydrocarbonbearing intervals. Reservoir characterization of the thin sands within the Raghavapuram Formation is effectively demonstrated using deterministic prestack inversion, incorporating RGT model output. The sands, encased within shale formations, represent a promising hydrocarbon source. Deterministic pre-stack inversion plays a crucial role in distinguishing sand from shale, primarily through analysis of the Vp/Vs ratio.