Evaluation of Facies Architecture and Depositional Environment of G-Field in the Greater Ughelli Depobelt of the Niger Delta Area, Nigeria

This study utilized well logs and core data to evaluate facies architecture and depositional environment of G-field in the Greater Ughelli Depobelt of the Niger Delta area in Nigeria. The study revealed five lithofacies unites, namely, Bioturbated Sandstone Facies (BSF), Coarse to Pebbly Sandstone Facies (CPSF), Mudsone Facies (MF), Very Fine Grained laminated Sandstone Facies (FGLSF), and Wavy- to Flaser-Bedded Facies (WFbF). The lithofacies were grouped into Two (2) Facies Assemblages that where established from the five mentioned lithofacies A-E. The Facies Assemblages are Open-marine Facies Association, Brackish-water Marginal-marine Facies Association and Tidal Flat Association. Gamma Ray (GR) logs within the cored interval defined an aggrading deposit. These assemblages were used to infer the various environments responsible for the deposition.