Sequence Stratigraphic Analysis Of Well ?X2? In The Niger Delta, South Eastern Nigeria

摘要

Sequence stratigraphic analysis was carried out on well ?X2? (interval 2590m -3300m) in the Greater Ughelli Depobelt of the Niger Delta based on wireline logs and biostratigraphic data. Standard laboratory preparatory and analytical methods were employed during the study and the data sets generated were integrated to construct a high resolution sequence stratigraphic framework for the study well. Results of the analysis revealed two (2) 3rd order depositional sequences and three (3) Maximum Flooding Surfaces (MFS 1, 2, and 3) dated ?33.0ma, ?31.3ma, and ?24.3ma respectively. The sedimentary units (mostly sandstone and shale intercalations) penetrated by the study well form part of the Agbada Formation of the Niger Delta and are of Early to Late Oligocene and younger ages. This age assignment is based on the co-occurrences of index foraminiferal taxa (Hopkinsina bononiensis, Spiroplectammina wrightii, Uvigerinella sparsicostata, Lenticulina grandis and Bolivina imperatrix) recovered from well ?X2?. The study well consists of Highstand System Tracts (HST) and Transgressive System Tracts (TST) which are made up of aggradational, progradational and retrogradational facies sequences.