Petroleum System Analysis of the Anambra Basin for New Exploration Opportunities

The Anambra Basin, straddling parts of Anambra, Enugu, and Imo states in South East Nigeria, is an established Cretaceous sedimentary basin with documented hydrocarbon shows and gas seeps, yet it remains significantly underexplored relative to its geological prospectivity. This study conducts a petroleum system analysis of the Anambra Basin, systematically evaluating source rock quality, reservoir presence, seal integrity, and trap geometry to identify undrilled exploration leads. Published geochemical data on the Awgu and Nkporo shale source rock intervals are reviewed to assess total organic carbon content, thermal maturity, and kerogen type using Rock-Eval pyrolysis literature data. Available well log data are used to characterise reservoir quality of the Ajali Sandstone and Mamu Formation sandstones. Regional seismic profiles interpreted in published studies are evaluated for structural and stratigraphic trap configurations. A burial history modelling approach is applied using one-dimensional basin modelling software to reconstruct the thermal history and hydrocarbon generation timing for the identified source intervals. Charge risk is assessed based on the spatial relationship between generative kitchens and identified structural closures. The study concludes by ranking identified leads by geological risk and recommending a phased exploration programme incorporating new two-dimensional seismic acquisition. This work provides a professional-level petroleum systems synthesis applicable to industry exploration planning and government resource assessment. Keywords: petroleum system, Anambra Basin, source rock, basin modelling, exploration.