Early to middle miocene sequence stratigraphy of well-5 (OML 34), Niger Delta, Nigeria

A sequence stratigraphic study was carried out on ditch cutting samples from well-5 (OML 34) in the Niger Delta in Nigeria. The sequence stratigraphic analysis based on foraminifera content and lithologic descriptions has revealed the following: five systems tracts (two transgressive systems tracts, two highstand systems tracts and one lowstand system tract); two third order maximum flooding surfaces (proposed at 3388 m and 3557 m dated 15.9 Ma and 17.4 Ma respectively) and two sequence boundaries proposed at 3301 m and 3466 m dated 15.5 Ma and 16.7 Ma respectively with the aid of index foraminifers present in the well (Praeorbulina glomerosa, Praeorbulina sicana, Orbulina saturalis and Catapsydrax dissimilis), as a result, three depositional sequences were established from the well intervals. These depositional sequences with the foraminifera species present in the well revealed that the well interval was exposed to two local depositional cycles (cycle 6 and 7), two regional cycles (cycles 2.2 and 2.3) within the TB2 super cycles corresponding to Haq et al. (1988) chronostratigraphic chart.