Lithologic and Biostratigraphic Correlations of Akata-7 and Oloibiri-1 Wells, Eastern Niger Delta, Nigeria

Abstract

Quantitative and qualitative foraminiferal biostratigraphy has been undertaken from the ditch cutting samples of Akata-7 and Oloibiri-1 wells located in the eastern Niger Delta, in view of determining the Lithology, foraminifera biozones, relative age, depositional environments and correlation. The Akata-7 and Oloibiri-1 wells which contain both planktic and benthic foraminifera, penetrated strata of Miocene age, and have been subdivided into biostratigraphic zones. The planktic zone established for these wells is Praeorbulina glomerosa Zone whereas the benthic zone is a taxon range zone of Poritextularia panamensis. Other sections of wells were barren or have sparse foraminifera content. Lithologically, both wells are correlatable as they are composed of shale and mudstone/siltstone with intervals of sand/sandstone. Biostratigraphically also, these wells correlate well on the basis of the established planktic and benthic zones. Littoral-deltaic to marine environments of deposition has been inferred for these wells on the bases of the occurrence of environmentally restricted benthic foraminifera species.