Palynostratigraphic Study of Well-X (Interval 700Ft-2180Ft), Offshore Niger Delta, South-South Nigeria

Abstract

A palynostratigraphic study of Well-X in the Niger Delta was carried out with a gamma ray log and a total of sixteen ditch cutting samples collected at different depth interval (700ft - 2180 ft), the samples were made up of sandstone, sandy shale and shale, depicting that the well penetrated Agbada Formation. The various samples were subjected to palynological analysis, the sixteen samples analysed yielded fair to good amounts of palynomorphs except two samples which had a poor recovery. The recovered palynomorphs include a high percentage of Pollen and Spores, some fresshwater algae (Concentricyst  circulus, Botryoccocus braunii) and a very minute amount of fungal spore, acritarchs and marine forms (Foram lining, Dinocysts, Leiosphaeridia), suggesting that the environment of deposition is terrestrial. A lithostratigraphic framework was established for the sample unit and a palynomorph distribution was constructed. From the distribution chart the percentage of the different palynomorphs (pollen, spores, freshwater algae, fungal spore, acritarch, marine forms and some undifferentiated forms) were calclated and used to generate a biostrati graphic plot that shows the Paleoenvironmental distribution of Well-X interval (700 -2180 ft). From the analysis, the sediments were observed to have been deposited during Early? Late Pliocene times. This interpretation is deduced by the co- occrrences of Stereiporites sp, Nympheapollis clarus and Cypereaopollis sp with Retistephanocolpites gracillis.