The C-37 prospect in the Tapti-Daman subbasin of Mumbai Basin (offshore of western India) was proved by one exploratory well in 1994. The discovery well produced gas and condensates from sandstone reservoirs of the Daman and Mahuva formations of, respectively, the Late and Early Oligocene. To test the updip extent of pay, one well was drilled 3.7 km from the discovery well, but hydrocarbons were not be found because the particular sand, which produced hydrocarbons, shales out there. 3D seismic data were acquired in 1996–97 and interpreted using instantaneous attributes and window-based attribute extraction. The stratigraphic and structural interpretation of the 3D data suggested two locations downdip, primarily for channel prospects, in Daman Formation. Minor gas shows were observed but pay sands were not encountered in the Mahuva. Seven wells are in the 3D survey area; one in the Daman and Mahuva formations (C-37 prospect) and one in Daman Formation (adjoining prospect) are hydrocarbon-bearing. Postdrill study suggests equivalent sands are absent at other well locations.