Seismic Interpretation for Stratigraphic Trap Identification in the Niger Delta

This study applies 2D seismic reflection interpretation to identify stratigraphic hydrocarbon traps in a subsurface dataset from the onshore Niger Delta, Rivers State, South South Nigeria. Stratigraphic traps formed by lateral facies changes, channel pinch-outs, and unconformity truncations represent significant remaining exploration potential in the mature Niger Delta petroleum province, where most conventional structural traps have been delineated. Identifying stratigraphic targets requires detailed seismic facies analysis and amplitude-versus-offset interpretation skills. This study interprets a public-domain 2D seismic line from the NIPEX data package, totalling 48 kilometres in the central Niger Delta onshore area. Interpretation is performed using Petrel academic licence software. Key horizons within the Agbada Formation paralic sequence are picked and correlated, and seismic facies analysis identifies reflection packages corresponding to distributary channel sands, mouth bar deposits, and shale barriers. Time-structure maps are produced for three identified target horizons. Amplitude extraction and bright spot analysis identify zones of anomalous amplitude associated with potential gas sands. Findings reveal four prospective stratigraphic configurations: two channel sand pinch-outs, one unconformity truncation, and one carbonate bioherm. Amplitude brightening exceeding two standard deviations above background is observed at the channel pinch-out locations. A depth conversion using a time-depth function from a nearby well confirms the structural relief and net thickness of the identified stratigraphic targets. The study recommends 3D seismic acquisition over the two channel targets as the next exploration step.

Keywords: seismic interpretation, stratigraphic trap, Niger Delta, Agbada Formation, amplitude anomaly.