SEQUENCE STRATIGRAPHIC STUDY OF BIWA FIELD IN GREATER UGHELLI DEPOBELT, NIGER DELTA, NIGERIA

High resolution biostratigraphic study of Biwa Field has enhanced the recognition of sequences (SB), Maximum Flooding Surfaces (MFS) and associated Systems Tracts. Three (3) sequences were identified from the base to the top of the study field with varying average thicknesses of sediments. The three (3) sequences, respectively and the candidate maximum flooding surfaces delineated were interpreted from the gamma ray log and biostratigraphic data. Sequence stratigraphic interpretations of the wells were performed and the chart produced is useful in further deepening the knowledge of the subsurface geology of the study field, Niger Delta area of Nigeria. The higher gamma ray and lowest resistivity readings were used to identify maximum flooding surfaces, which were further established with biostratigraphic data. The sequence stratigraphy of the well was attempted based on the presence of some selected marker fossils. The studied interval was dated Oligocene to Early Miocene base on the geologic ages of Sequence Boundaries (SB) and positions of Maximum Flooding Surfaces (MFS) interpreted which range between sequence I (F7800, P630) ? 23.7Ma, sequence II (F7600, P580) ? 29.3Ma and sequence III (F7600, P560) ? 32.4Ma. The MFS were between 23.3Ma, and 31.3Ma. The sediment in the study area correspond to the sedimentary facies deposited in the Greater Ughelli depobelt