Abstract

The aim of this study is to carry out Sedimentological core description in order to characterize the different depositional environments of the reservoir sandstones in “SCOJAS” -43 well. The depositional environments were used to define the geometry of the hydrocarbon reservoir. Detailed Sedimentological core description and interpretation yielded the different depositional environments. Sedimentological studies of four hundred and eleven feet (411ft) length of core covering 6233.2 metres to 8773.2 metres from “SCOJAS” -43 well was carried out using slabbed core samples with the aim of determining lithofacies association. Thirteen (13) Lithofacies units were identified within the cored interval. They include, Massive-Laminated Sideritic Mudstone, Fossiliferous Sandstone, Fossiliferous Mudstone, Bioturbated Muddy Heterolith, Massive-Parallel Laminated Sandstone, Planar Laminated Sandstone, Massive-Laminated Mudstone, Current Rippled Sandy Heterolith, Hummocky/Swaley Cross Stratified Mudstone, Cross-Bedded Medium-Fine Grained Sandstone, Cross-Bedded Coarse-Gravelly Grained Sandstone, Bioturbated Medium-Fine Grained Sandstone and Current Rippled Sandstone. Seven (7) Lithofacies Associations were identified within the cored interval; they include Marine Shales, Bioturbated Channel Heterolithic, Stratified Channel Heterolithic, Tidal Channel Heterolithic, Proximal Lower Shoreface Heterolithic, Fluvial Channel Sandstone and Coastal Plain Sandstone. These lithofacies associations can be further categorized using the three major types of depositional environments. Fluvial Channel Sandstone and Coastal Plain Sandstone are continental, Bioturbated Channel Heterolithic, Stratified Channel Heterolithic and Tidal Channel Sandstone are transitional while Marine Shales and Proximal Lower Shoreface Heterolithic are marine. This study was able to reconstruct the environment of deposition of “SCOJAS” -43well, which will be very useful for reservoir modelling.