Afenmai Field is a partially assessed discovery within the central depobelt of the eastern Niger Delta Basin in Nigeria. It occupies 242 km² surface area and presently has eight wells, giving it an average well density of one well per 31 km². Improved assessment of the discovery is required to upgrade the field to development drilling status. As a contribution to improving the assessment, this study characterized the E8000 sand, which bears hydrocarbon in well 007. The data utilized comprised information on subsea vertical depth to top and base of sand and shale units, foraminifera content, geophysical logs, checkshot data, fluid contact depths, and 3D seismic volume. Sequence stratigraphic concepts were employed to analyze the sand and shale units, foraminifera content, and geophysical logs. The E8000 sand was mapped through the 3D seismic volume, and a depth-structure map was produced. The map reveals a major structure building synthetic fault in the middle of the field. The fault runs approximately east-west in the eastern part of the field and northwest-southeast in the western part. The sand is a lowstand systems tract with a roll-over anticlinal structure that forms a three-way closure with a crestal synthetic fault. The reservoir pay occupies about 4.5 km² areal extent, with opportunities for drilling four development wells along the east-west axis of the closure. Opportunities exist for drilling a minimum of three development wells southwards of well 007. Approximately 4000–5000 root mean square amplitude values characterize hydrocarbons in the reservoir. A prospect is generated within the eastern part of the major structure building fault’s upthrown block.