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Abstract
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.
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.
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