Browsing by Author "Onwualu, Nneka Emelda"

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    Sequence stratigraphic interpretation of wells 1,2,3 & 4 in the "GERA" field, Greater Ughelli Depobelt, Niger Delta Basin, Nigeria
    (Federal University of Technology, Owerri, 2014-02) Onwualu, Nneka Emelda
    A sequence stratigraphic approach was employed to understand sediments penetrated in Gera Field situated in the Greater Ughelli Depobelt, Central Niger Delta Basin. The technique incorporates biostratigraphic and well log data in constructing a high resolution sequence stratigraphic framework for the field. The analysis of the above data sets enabled the subdivision of the transverse part of the stratigraphic column within the field into sequences and system tracts. Four 3rd order Maximum Flooding Surfaces (MFS) and their intervening sequence boundaries (SB) were interpreted in the area. Three depositional sequences were interpreted within the field and were subdivided into transgressive systems tract and highstand systems tract. Four maximum flooding surfaces correlate with the 28.1Ma, 31.3Ma, 33.0Ma and 34.0Ma of the transgressive marker shales of the Niger Delta Chronostratigraphic Chart. The 28.1 million years (Ma) MFS (G. Opima Opima) with its distinct log signature, constitutes the regional seal rock while the different sequence boundaries act as excellent reservoirs of the field. Of the four sequence boundaries, only one was found to be truly Type-1 sequence boundary, while the other three could not be convincingly attributed to a Type-1 sequence boundary, since a lowstand systems tract does not overlie them. The age of sediments penetrated in Gera field is found to range from Early – Late Oligocene as deduced from the foram zonations of wells in the field.