Seismo-Stratigraphic Framework for Stratigraphic Trap Characterisation in the Lower Cretaceous Sequence of the Benue Trough

This study develops an original seismo-stratigraphic framework for identifying and characterising stratigraphic hydrocarbon traps in the Lower Cretaceous sequence of the Benue Trough, North Central Nigeria. The Benue Trough was formed as an intracratonic rift during the opening of the South Atlantic, and its Lower Cretaceous carbonate and clastic sequences contain potential source rocks, reservoir sands, and evaporite seals that together constitute an unrecognised petroleum system. This study integrates newly acquired 2D seismic reflection data (totalling 340 kilometres) with the reinterpreted NGSA legacy 2D seismic database and borehole control from abandoned deep exploration wells in Benue, Kogi, and Nasarawa States. Sequence stratigraphic analysis using Wheeler domain transformation identifies systems tracts and sequence boundaries. Seismic facies analysis characterises depositional environments. Spectral decomposition and geological tuning analysis identifies reservoir architecture at sub-seismic scale. Source rock maturity modelling integrates time-temperature history with geochemical data from available well samples. Findings reveal five depositional sequences separated by regional unconformities within the Albian to Santonian succession. Two carbonate build-up sequences show bioherm morphologies with characteristic seismic facies consistent with reef and mound structures that constitute primary trap types. Organic-rich dark shales in the Lower Albian Asu River Group show total organic carbon values of 1.2 to 3.8 percent, meeting source rock criteria. Burial history modelling indicates peak maturation at present-day burial depths in the deepest sub-basins. The study establishes an original seismo-stratigraphic model that defines testable stratigraphic play concepts for renewed Benue Trough exploration.

Keywords: seismo-stratigraphy, Benue Trough, stratigraphic trap, Lower Cretaceous, petroleum exploration.