The application of wellsite biostratigraphic technique has aided the reconstruction of the subsurface
geology in the Nigerian deepwater region. It has further aided decision making during drilling operations
including the planning of well paths. Critical decisions regarding casing setting, coring point selection,
overpressure zone determination and total depth picks, are easily achieved through confirmation of well
prognosis and correlation to offset wells. This technique is very important in the tectonically active Nigerian
deepwater region which is characterized by varying degrees of both syn-depositional and post-depositional
deformation. Accurate interpretation of basin architecture, lateral variation and facies change is
required before drilling. Confirmation of well prognosis during drilling operation is equally important.
It has been proved that wellsite biostratigraphic technique helps to ‘‘get it right at first’’ when integrated
with the traditional lithologic description, log signature correlation and seismic profile interpretations.
The modern and rapid processing technique of calcareous nannofossil, for instance, provides
‘real time’ result for the exploration team for confirmation of, or adjustment to, the drilling program.
The attendant contribution in saved time, cost and safe and successful drilling operation makes the technique
beneficial for all operators.
This paper presents practical experience of wellsite biostratigraphy application in three oil prolific
Nigerian deepwater regions: the Niger Delta, Joint Development zone of Nigeria/Sao Tome and Principe
area (JDZ) and Benin (Dahomey) Basin.
2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-NDlicense