Abstract

Eastern offshore basin (Fig. 1) is one of the most promising deep water block with several discoveries. After extensive exploration, it is now under development phase. Reservoirs in this area are sands within Godavari clay of Plio-Pleistocene age. These reservoirs are the slope channel sands which occur as high amplitude anomaly bursts within low to moderate amplitudes pertaining to encasing clay in the background. Capturing these high amplitude anomalies as geobodies bring out the geometry of NW-SE trending slope channel sands and the data from the drilled wells targeting them confirm that these high amplitude bursts to be correspond to coarser clastics. Most of these sand bodies are charged with hydrocarbons. However, as observed in some wells these high amplitude events, though correspond to reservoir sands, are not always hydrocarbon bearing. These surprises may pose a challenge during development phase. To understand and overcome this challenge, a reservoir characterization study through Pre-stack inversion and Fluid & Facies Probability analysis was carried out. A meticulous approach of integrating well logs and seismic data was adopted. Petrophysics and Rock Physics Modelling was carried out in the available wells to overcome the challenges due to unconsolidated nature of reservoir sands, thinly laminated sand and shale alternations, variation in shale/ clay stone elastic properties. The input for this study was PSTM gathers. Gathers were subjected to gain application and remnant multiple attenuation.