Palynofacies Investigation of Sediments from Ore-1 Well and its Paleoenvironmental Studies, Western Niger Delta, Nigeria

Abstract

Palynofacies investigation of the sediments from 9700 ft - 1350 ft intervals of Ore-1 well, western Niger Delta, Nigeria was carried out. The study is aimed at delineating palynostratigraphic zones and established paleoenvironment of the sections. Forty-three ditch cutting samples were subjected to standard technique of palynofacies analysis using the acid method and the recovered palynomorphs were examined under the CX41Olympus binocular transmitted light microscope. Lithologically the section comprises of fine to medium grained, orange to dark coloured sandstone units and dark shale units. Palynofacies analysis yielded moderately rich palynomacerals and palynomorphs. Palynomacerals recorded show more than 90% of palynomaceral 1 (orangebrown or dark brown structured and unstructured higher plant materials), over 80% of palynomaceral 2 (structureless or structured materials of rootlet relics, stem, leaf and relics of algal and less than 30% of palynomaceral 3 (leaf cuticle and irregular relics of plants) and approximately 4% of palynomaceral 4 (dark blade, tube and needle like shape materials with cellular structure). Palynomorph assemblage of the recovered organic content was less than 5%.Three interval palynostratigraphic range zones of Verrucatosporitesusmensis - Ctenolophoniditescoastatus, Pachydermitesdiederixi - Spinicolpitesechinatus and Grimsdaleapolygonalis–Retibrevitricolopitestriangulatus were recognized. These zones were dated early to late Eocene based on the recovered marker palynomorphs such as Douladiteslaevigatus, Ctenolophoniditescoastatus, Psilamonocolpitesmarginatus, Retitricolporitesirregularis and Sapotaceae. A coastal-deltaic (lower delta and upper delta plain) environment have been inferred for the studied section of Ore-1 well.