SEQUENCE STRATIGRAPHY ANALYSIS AND RESERVOIR CHARACTERIZATION OF THREE WELLS IN UH OIL FIELD NIGER DELTA BASIN NIGERIA

Abstract

Three wells in UH field of Niger Delta were studied to erect sequence stratigraphy framework and hydrocarbon reservoir potential within the Niger Delta Basin. Biostratigraphy data (foraminifera and palynology), wireline logs and paleobathymetry data were used in this study. Thirteen major stratigraphic bounding surfaces (seven depositional sequence bounded by eight sequence boundaries (SB) 13.1 Ma to 3.7Ma which mark the onset of marine flooding and turnarounds from progradational facies to retrogradational facies during sequence buildup were delineated. Seven maximum flooding Surfaces (MFS) 12.8Ma to 3.9 Ma which characterized by marker shales, high faunal abundance and diversity were identified and correlated along the strike line of three wells base on their stratigraphic surfaces and relative age which showed sequence thickening from landward to basinward region. The delineated sequences comprise of lowstand system tract (Progradational packages), Transgressive system tract (Retrogradational packages) and High stand system tract (Aggradational packages) which reflect depositional systems deposited during different phases of sea level rise and fall. The delineation of paleoenvironment using biofacies and wireline logs showed delta plain to open shelf. Paleobathymetry panel indicated that the sediment were deposited within inner neritic to Bathyal environment dated Mid-miocene to late Miocene (12.8Ma-3.9Ma) in age. These integrated interpretations suggest that the sequences may hold potential source, reservoir and seal rocks for hydrocarbon exploration.