Insight into sequence stratigraphic and structural framework of the onshore Niger Delta Basin: Integrating well logs, bi
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ORIGINAL PAPER
Insight into sequence stratigraphic and structural framework of the onshore Niger Delta Basin: Integrating well logs, biostratigraphy, and 3D seismic data Chidozie Izuchukwu Princeton Dim 1 & K. Mosto Onuoha 1
Received: 22 June 2016 / Accepted: 12 June 2017 / Published online: 11 July 2017 # Saudi Society for Geosciences 2017
Abstract Stratigraphic and structural interpretative studies have been carried out within the paralic sequence of Agbada Formation in the Niger Delta Basin. The method of study involved integrating sequence stratigraphic techniques with well logs, biostratigraphy, and 3D regional seismic data obtained from several producing fields in the Coastal Swamp depobelt of the onshore Niger Delta Basin. This was targeted at establishing regional sequence stratigraphic and structural framework from well log correlation and seismic mapping so as to better define hydrocarbon leads. Well log correlation using stratigraphic bounding surfaces such as maximum flooding surfaces (MFSs) and sequence boundaries (SBs) indicates that the stratigraphic package was deposited within the Middle to Late Miocene (8.5 to 12.1 Ma) age. Recognized depositional sequences revealed differential thickening and thinning of the associated system tracts (lowstand system tract (LST), transgressive system tract (TST), and highstand system tract) (HST)). This observed stratal behavior has been attributed to the influence of syndepositional tectonic structures that characterize the Coastal Swamp depobelt, which lies within the extensional zone. Flattening of MFSs at various ages indicates observable basinward shift of the depositional center. The genetic units of LST and HST serve as good hydrocarbon reservoir whereas HST and TST constitutes mainly the source and seal packages rocks in the area. Structural interpretation revealed the occurrence of simple/faulted rollover anticline, collapsed crest, * Chidozie Izuchukwu Princeton Dim [email protected] K. Mosto Onuoha [email protected] 1
Department of Geology, Faculty of Physical Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
regional hanging wall and footwall, horst block, and subdetachment fault structural styles that constitute the key hydrocarbon entrapment mechanisms. Structural top maps show fault-dependent closures which dominate the extensional zone, which could form possible hydrocarbon leads and prospects that should be targeted during exploration studies for development. Keywords Sequence stratigraphy framework . Structural framework . Entrapment mechanism . Coastal Swamp depobelt . Niger Delta Basin
Introduction The paralic sequence of the Agbada Formation occurring within the Coastal Swamp depobelt is among the most challenging successions in stratigraphic and structural interpretations of the Niger Delta Basin. This is due to the several factors involved in its tectono-stratigraphic evolution. The sediment packages of this sequence in the Niger Delta Basin are thick, complex sedimentary units deposited rapidly during high-freq
