Foraminiferal Distribution, Stratigraphy and Palaeoenvironment of the U-12 Well, Niger Delta Basin, Nigeria

Ditch cutting samples recovered from interval 2008 - 3396 metres and well logs from the U-12 well, northern depobelt of the Niger Delta basin were used for foraminiferal, lithologic and palaeoenvironmental analyses. The standard methods of foraminiferal sample preparation which involved disaggregation and washing of samples through a 63 micron mesh sieve, drying and picking of the foraminifera and other accessories were used. The lithologic analysis and foraminiferal recovery revealed the penetration of the paralic Agbada Formation comprising of sediments which were dated Late Eocene - Early Oligocene age. The P16/17-P18/19 planktonic foraminifera zones were delineated for the study well section, Palaeoenvironmental analysis based on the triangular plot of the foraminifera suborder ratio, oxic foraminiferal indicators and the relationships between paleotemperatures and planktic foraminifera revealed that the well sediments were deposited under the prevalence of normal marine salinity, oxygenated water and cool temperature conditions. The paleobathymetry ranged from non-marine through shallow inner neritic, inner neritic, middle neritic to outer neritic environments based on the distribution of the foraminifera. The results of this study will be useful for correlation, dating and stratigraphic characterization across several fields in the Tertiary (Paleogene) rocks of the Niger Delta Basin.