Age Evaluation of Sapele Shallow Field, Niger Delta, Southern Nigeria

The study area is synonymous with poor reservoir performance which is evidenced after physical investigation was carried out by SEPLAT drilling and production team. Hence, wells are constantly serviced to burst production. This led to the evaluation of the subsurface geology of the study area using well logs, and biostratigraphy data, to acquire a better understanding of the geological age and depositional environment of the study area. Five Maximum Flooding Surfaces (MFS) were delineated and correlated across the field and very few marker faunas were present due to its proximity to the surface and they are of Late Miocene to Early Pleistocene age as established through the delineated regional seal of marine transgression. Also, six Sequence Boundaries (SB) were delineated and correlated across all wells in the study from oldest to youngest sequence. The oldest sequence boundary delineated was dated SB_4.1 ma. This surface represents a substantial erosional surface defined before the MFS_3.8 ma. Other sequence boundaries delineated are dated 3.7, 3.0, 2.4, 1.6 and 0.8 ma respectively. This corroborates with SPDC (2010) and the work of other researchers in the Niger-Delta oil field.