Palynostratigraphy and Paleoenvironmental Evaluation of V-Well In Y-Field Offshore, Niger Delta Basin Nigeria.

Abstract

Palynostratigraphy is the application of palynology to stratigraphy. Sixty-four ditch cuttings, sampled at 20 meters intervals from V-well Offshore, Niger Delta were analysed. The aim was to utilized palynological principles to characterize the sediments recovered, and to reconstruct the paleoenvironment of deposition of the sediments in the studied well. Lithologically, the samples consist of predominantly of fine to medium grained sand with shale intercalation which conformed to the paralic Agbada Formation. The samples were subjected to the standard palynological laboratory processes which involved the maceration of samples with acids and bases. The recovered palynomorphs were abundant and diversified. Some of the recovered palynomorphs, such as; Zonocostites ramonae, Monoporites annulatus, Nympheapollis clarus, Stereisporites sp, Cyperaceoporites sp, Podocarpus milanjianus, Cincitiperiporites mulleri, Multiaerollites fomorsus, Echiperiporites echinatus, Gemmamonoporites sp, Peregrinipollis nigericus, Belskipollis elegance, Echiperiporites estelae, Botryococcus braunii, Dinoflagellate cysts, Spiniferites sp, Racemonocolpites hians and Echiperporites sp, were used in dating, zoning and interpreting the paleoenvironment of deposition of the studied section. Four subzones were identified based on the first appearance datum and last appearance datum of Nympheapollis clarus, Stereisporites sp, Peregrinipollis nigericus, and Cyperaceopolis sp. The stratigraphic intervals were assigned Late Miocene – Early Pliocene. The integration of land derived palynomorphs and marine indicators suggest that the sediments were deposited within the upper – lower shoreface (shallow marine).