FORAMINIFERA AND AGE CHARACTERIZATION OF WLL X, ONSHORE NIGER DELTA, NIGERIA

Ajogu, G. E. and Asadu,  A.N
Department of Earth Sciences, Federal university of Petroleum Resources Effurun, Nigeria.
Correspondence e-mail: asadu.anthonia@fupre.edu.ng

ABSTRACT

Micropaleontological analysis was carried out on one hundred and ninety-two (192) ditch cutting rock samples from interval, 5480 feet to 11256 feet of well-x, located between Longitude 0 3’47.677″E and latitude 0 2’30.506″N, onshore Niger Delta, The aim of the study was to erect biozonation model of foraminifera and use it to characterize the age of the sediments penetrated by the well section studied. The sedimentological sample investigation involved wet and dry sieve analysis using 63 micrometer mesh size, 250 micrometer mesh size and 500 micrometer mesh size while the micropaleontology samples was prepared through wet sieve analysis with sodium hexametaphosphate as a deflocculant and analyzed for foraminifera following the taxonomic classification of  Loeblich and Tappan (2015) method for foraminifera analysis. The sedimentological description of the ditch cutting rock samples provided data for sand / shale ratio, sorting and gradational profile of the study well and show that the sediment under study penetrated the Parallic Agbada Formation. Micropalaeontological analysis result indicated that some intervals yielded a rich recovery of foraminiferal assemblage while other intervals were either completely barren or recorded few occurrences of foraminifera. A total number of Ninety-three (93) well preserved foraminiferal species were identified. Calcareous benthonics accounted for about 35% of the total recovery while the agglutinated benthonics constituted about 42% and the planktonic species made up the remaining 23%. Three biozone (Haplophragmoides sp, Valvulina flexilis / Haplophragmoides compressa and Globigerinoides ruber/ Alveolophragmium crassum) were recognised and compared with, ?N19/20, N18 – N19/20 and N17 of Blow (1979) zonation scheme respectively to assign early Pliocene to Late Miocene age for the rock succession studied.

Keywords: Foraminifera, micropaleontology, Age, Biozonation, Niger Delta, Sedimentology.