E. G. Maju-Oyovwikowhe

This study integrates sedimentological, mineralogical, and palynological analyses to evaluate the depositional environments and hydrocarbon potential of the XY Well in the Niger Delta Basin. The well penetrates the Agbada Formation, which forms part of the paralic sequence of the Niger Delta. A total of 190 ditch cutting samples were analyzed using standard sedimentological and palynological procedures to determine their lithological composition, textural characteristics, mineral assemblages, and fossil content. The lithological succession consists predominantly of alternating sandstone, shale, sandy shale, and clayey sand units typical of deltaic successions.
Mineralogical studies revealed quartz, pyrite, glauconite, iron oxide, mica, and carbonate minerals, suggesting mixed continental and marine influences, moderate diagenetic alteration, and cyclic depositional energy conditions. The sand units are moderately to well sorted, subrounded to rounded, and interpreted as potential reservoir facies, whereas the shales serve as potential source and seal rocks. Palynological analysis yielded 964 palynomorphs comprising 496 pollen grains, 458 spores, and 10 dinoflagellate cysts. Diagnostic taxa such as Praedapollis africanus, Peregrinipollis nigericus, and Retibrevitricol porites obodoensis enabled the
establishment of three biostratigraphic zones (P620, P580, and P560) corresponding to the Miocene age. Thirteen informal palynological zones were also recognized, reflecting alternating terrestrial, marginal marine, and shallow marine environments. Integration of the sedimentological and palynological results indicates a regressive–transgressive depositional cycle characteristic of a prograding delta system comprising delta plain, delta front, and prodelta
facies. The study concludes that the Agbada ormation penetrated by the XY Well exhibits favorable reservoir and source rock characteristics, confirming its significance in the hydrocarbon system of the Greater Ughelli Depobelt of the Niger Delta Basin.

The Niger Delta Basin is one of the most productive hydrocarbon regions globally, yet its complex depositional history, structural variations, and diagenetic processes present challenges 9 for reservoircharacterization and hydrocarbon exploration. This study integrates lithofacies analysis, mineralogical evaluation using X-ray diffraction (XRD), and petrophysical assessment to enhance the understanding of reservoir quality and hydrocarbon potential in the EstyWil-1 Well, located in the Northern Delta Depobelt. Lithofacies analysis indicates a transition from fluvial-deltaic to deep marine depositional environments, characterized by alternating layers of sandstone, shaly sandstone, sandy shale, and thick shale. Sandstone-rich intervals, particularly within distributary channels and delta-front facies, exhibit high porosity (25-32%) and permeability (500-1500 mD), making them favorable for hydrocarbon accumulation. In contrast, shaly interbeds and deep marine shale sequences serve as barriers that influencefluid flow and hydrocarbon entrapment. Mineralogical analysis reveals a predominance of quartz, along with kaolinite, illite, chlorite, and feldspar, all of which impact reservoir quality. High quartz content enhances porosity, whereas clay minerals, particularly illite and chlorite, contribute to permeability reduction. The presence of pyrite and carbonate minerals in deeper sections suggests reducing conditions, which favor organic matter preservation and potential hydrocarbon generation. Petrophysical analysis, incorporating gamma-ray, resistivity, neutron-density, and sonic logs, confirms the presence of hydrocarbon-bearing zones with low water saturation (Sw <40%) in productive intervals. Structural interpretations highlight the role of growth faults and rollover anticlines as primary trapping mechanisms that enhance hydrocarbon accumulation. By integrating sedimentological, petrophysical, and mineralogical data, this study provides a more comprehensive approach to reservoir characterization. The findings contribute to improved exploration strategies, optimized reservoir management, and enhanced oil recovery (EOR) techniques within the Niger Delta Basin.