Abstract

Hydrocarbon find from the Oligocene basal sand in well X of Ichapur provided a significant lead to the exploration in this part of the Bengal Basin which lies up dip of the hinge zone. Integrated interpretation of 3D data along with the well data reveals that the Oligocene Basal sands of Ichapur were initially deposited as river mouth bars over the Hoogly shale and subsequently reworked by tidal currents. Horizon slices through the composite pack depict the spatio-temporal distribution of this pack in the study area. Reservoir sand of well X may not extend up to well Y either because of facies variation as envisaged from the seismic attributes or due to permeable barrier between the two wells and occur as discontinuous individual reservoirs. A better reservoir to the east of well X and well Y is also envisaged. The anticlinal wrap around well X, as seen in the seismic section is depicted to be a velocity pull up feature, attributed to the lateral velocity variation in the shallower levels caused due to the presence of younger channel systems in the area. In absence of any prominent structural style, the entrapment of oil in well X is envisaged to be strati-structural.