Abstract

Delineation and characterization of Miocene reservoirs in the Mumbai Offshore basin pose multiple challenges as their lithology and petrophysical properties vary greatly not only with their depositional environment but also with the post-depositional diagenetic process. Independent analysis of each of the processes is required to address the complexities of such reservoirs. Clastic channel reservoirs of the Miocene age along with carbonate reservoirs have been established in the basin and the depositional environment plays a great role in the distribution of lithological/petrophysical properties within the reservoir. Thus, a prior understanding of geomorphology may provide valuable information for the characterization of the reservoir. 3D seismic attributes such as, variance, curvature, sweetness, and spectral decomposition were used for the identification of channel geometry and fault patterns. Seismic attributes were also utilized for the characterization of the carbonate reservoir. Based on the analysis, a conceptual geological reservoir model of the atoll phase reef was envisaged. Further, seismic interpretation in the Wheeler domain and post-stack inversion was also performed which reinforced the envisaged geological model. Recently, one well was drilled which was falling on good facies in the envisaged model and it encountered better facies development as anticipated from the model.