Abstract

Lower Mahuva formation in Tapti Daman sector is primarily over pressured shale/claystone deposited in lowenergy environment whereas Mukta formation a homotaxial of Upper Mahuva formation comprises dominantly Limestone and Shale deposited in changing energy conditions. Lower Mahuva formation andMukta formation belong to the Early Oligocene period. Presence of hydrocarbon is well established in Muktaformation in the Mumbai offshore area particularly in the central Graben areas. The development of thickLimestone beyond Diu fault towards north of Mumbai High area in Tapti Daman sector in Saurashtra offshorejuxtaposed with Lower Mahuva formation shale has been observed in some wells. Global sea level rise andclastic influx from the North East of the Tapti Daman sector played major role in the process of limestonedeposition. Along the NE-SW trending shelf hinge these limestone are deposited as Autothonous deposits. Theassemblage of Benthonic and planktonic fauna suggest bathymetry inner neritic environment. The clasticsupply from the northeast was not enormous and the basin was starved. The limestones are hard, compact and fossiliferous in nature. Primary porosity has been reported from the cores cut in the wells of the area. Secondary porosity has also developed. The amplitude maps in 3D seismic data detremine the depositional trend of these limestone deposits anongwith inversion study suggest the broad locale for better reservoir development.