Sequence Stratigraphic Interpretation of XY-Field Onshore Niger Delta Basin Nigeria

Abstract

Wireline logs and biostratigraphic data were integrated to attempt the sequence stratigraphy of “XY field” onshore Niger Delta Basin which revealed three depositional sequences. Four sequence boundaries and three maximum flooding surfaces dated (17.7, 16.7, 15.5, and 13.1Ma) and (17.4, 15.9, 15.0 Ma) respectively were identified in both Wells. The delineated sequences comprised Lowstand Systems Tracts (LST), Transgressive Systems Tracts (TST) and Highstand Systems Tracts (HST), which reflect depositional systems deposited during different phases of base level changes. The sands of LST and HST show good reservoir qualities while the shales of the TSTs could form potential reservoir seals. Integration of lithofacies and biofacies data suggests that the depositional environments ranges from transitional to Outer Neritic environment.