Abstract

The 3-D seismic and well data of B-12/C-26 area of Tapti-Daman sub-basin of Mumbai Offshore Basin, India, have been evaluated for mapping of reservoir facies and entrapments within Daman Formation of Upper Oligocene age. The seismic data have been interpreted with application of sequence stratigraphy, 3-D visualization, seismic attribute analysis, coherency, and AVO analysis methods. The basic framework for analysis was defined by correlating bottom and top reflectors of Daman Formation and four internal reflectors. Application of concepts of sequence stratigraphy on logs and seismic data revealed formation of incised valleys in the upper part of Daman Formation. These valleys were filled by fluvial/ estuarine channels which are oriented in east-west direction. In the middle and lower part of Daman Formation, channels are oriented in northeast-southwest direction and are distributary-fills in nature. Depositional geometry and internal facies variations of channels were inferred from seismic attribute maps, coherency and AVO attribute slices. Thick sandstones are inferred in fluvial/estuarine and distributary channels. Stratigraphic entrapments are envisaged for lower and middle channel sandstone reservoirs.