Publication Title Paleoenvironments and hydrocarbon reservoir potentials from the selected sedimentary basins in Nigeria using sedimentary facies and textural analyses
Publication Type journal
Publisher Journal of Sedimentary Environments
Paper Link https://doi.org/10.1007/s43217-022-00101-x
Publication Authors Godwin Okumagbe Aigbadon1 · Azuka Ocheli2 · Obinna Chigoziem Akakuru3 · Ernest Orji Akudo1 · Simon Dalom Christopher1 · Ogaga Esharive1 · Joseph Amobi Francis1
Year Published 2022-04-15
Abstract Sedimentary facies, petrographic, textural, and mineral analyses of sections of conglomerates/pebbles and sandstone facies of the Lokoja and Patti Formations in southern Bida Basin, Ajali and Abeokuta Formations in the Anambra and Dahomey Basins in Nigeria respectively were carried out. These analyses aimed at deciphering the paleo-environment and reservoir potential of the formations. The study entailed feld observations, petrographic, mineralogical (using X-ray difractogram), granulometric, and pebbles morphological analyses. The ffteen lithofacies were identifed and grouped into three main facies associations. The petrological results revealed that the dominant minerals are quartz, feldspar, and clay. The mineral analysis (XRD) also shows that quartz is predominant; the granulometric result shows that the formations are characterized by poor to well-sorted, strongly coarse to strongly fne skewed, and mesokurtic to leptokurtic sandstone grains. Pebble morphometric indices indicate fuvial to shallow marine felds. The integration of the sedimentary facies and textural analyses is suggestive of the shallow marine subtidal channel, subtidal wave, and estuarine mudfat environments with strong fuvial infuences. Based on textural statistical and mineral analyses, the sandstones are moderately matured to immature, and the reservoir quality of sandstone facies is classifed as good to very good in Lokoja, Ajali, and Abeokuta Formations and very poor to poor in Patti Formation. The areas that are potential and non-potential hydrocarbon reservoirs have been identifed which will be benefcial to petroleum industries.
Publication Title Granulometric and pebble morphometric applications to Benin Flank sediments in western Anambra Basin, Nigeria: proxies for paleoenvironmental reconstruction
Publication Type journal
Publisher Environ Monit Assess (2018) 190:286
Paper Link https://doi.org/10.1007/s10661-018-6637-z
Publication Authors Azuka Ocheli & Anthony Uwaoma Okoro & Ovie Benjamin Ogbe & Godwin Okumagbe Aigbadon
Year Published 2018-08-22
Abstract Integrated granulometric and pebble morphometric study of Late Cretaceous rocks of the Benin Flank, Nigeria, were used to delineate depositional process and environment of the rocks in the study area. Granulometric analysis reveals that the sandstones of the Lokoja Bassange Formation have an average graphic mean (Mz) of 0.59? (coarse grains), inclusive graphic standard deviation (?i) of 1.36? (poorly sorted), graphic kurtosis (Ka) of 1.12? (leptokurtic), and inclusive graphic skewness (Ski) of ? 0.14? (stongly coarse skewed). The sandstones for the Mamu Formation have an average Mz of 1.42? (medium grains), inclusive graphic standard deviation (?i) of 0.74? (moderately sorted), graphic kurtosis (Ka) of 1.43? (leptokurtic), and inclusive graphic skewness (Ski) of 0.02? (nearly symetrical). The sandstones for the Ajali Formation have an average Mz of 1.23? (medium grains), inclusive graphic standard deviation (?i) of 1.21? (poorly sorted), graphic kurtosis (Ka) of 1.46? (leptokurtic), and inclusive graphic skewness (Ski) of ? 0.17? (nearly symetrical). Pebble morphometric analysis of the larger grains reveals that the mean values of elongation ratio (ER) = 0.69, coefficient of flatness (FI) = 54.90%, oblate–prolate index (OPI) = 3.34, the maximum projection sphericity index (MPSI) = 0.75, form = 0.67, and roundness (?) = 36.28% for the Lokoja Bassange Formation; ER = 0.76, FI = 37.07%, OPI = ?3.20, the MPSI = 0.53, form = 0.38, and ? = 52.93% for the Mamu Formation; and ER = 0.72, FI = 47.44%, OPI = 1.12, the MPSI = 0.67, form = 0.54 and ? = 42.68% for the Ajali Formation. The integration of the various granulometric and pebble morphometric data, different bivariate and ternary plots indicate fluvial environment for the Lokoja Bassange Formation, dominantly shallow marine environment for the Mamu Formation and fluvial – shallow marine environment for the Ajali Formation. This study shows that the Benin Flank, western Anambra Basin has a depositional setting radiating between fluvial and shallow marine environments.
Publication Title Appraising the risk level of physicochemical and bacteriological twin contaminants of water resources in part of the western Niger Delta region
Publication Type journal
Publisher Environ Monit Assess (2020) 192: 324
Paper Link https://doi.org/10.1007/s10661-020-08302-5
Publication Authors Azuka Ocheli & Onyeka Benjamin Otuya & Star Otitie Umayah
Year Published 2020-05-23
Abstract This study was carried out to assess the physicochemical and bacteriological contaminants of surface, shallow well and municipal borehole waters in part of the western Niger Delta as a way of safeguarding public health against waterborne diseases. A total of 72 water samples collected from the study area were analysed and their results show that the pH average value ranges from 6.2 in the dry to 8.5 in the rainy seasons for surface water, 6.6 and 8.3 for shallow well water and 6.5 to 8.4 for borehole water. The turbidity in surface water varies from 8.1 to 26.2 Formazin Attenuation Unit (FAU), 0.3 to 2.9 FAU in shallow well water and 0.4 to 4.8 FAU in borehole water. Electrical conductivity (EC) value varies from 1010 to 1840 ?s/cm for surface water, 201 to 950 ?s/cm for shallow well water and 670 to 1650 ?s/cm for borehole water. Total dissolved solids range from 0.1 to 2.6 mg/l in surface water, 0.2 to 4.1 mg/l in shallow well water and 0.3 to 4.4 mg/l in borehole water. The value of the total hardness ranges from 44 to 120 mg in surface water, 46 to 96 mg in shallow well water and 70 to 130 mg in borehole water. The nitrate value ranges from 1.1 to 10.6 mg in surface water, 3.0 to 8.4 mg in shallow well water and 3.7 to 9.6 mg in borehole water. The value of sulphate content varies from 4.6 to 38.5 mg in surface water, 6.2 to 34.8 mg in shallow well water and 5.7 to 55.7 mg in borehole water. The value of phosphate concentrations in surface water varies from 1.0 to 9.0 mg, 0.7 to 3.4 mg in shallow well water and 1.0 to 4.7 mg in borehole water. The bacteriological analysis using the membrane filtration technique revealed the presence of faecal bacteria and total coliform counts. The presence of the analysed twin contaminants in the studied water resources reduced their water quality. The physicochemical and bacteriological data were subjected to statistical and correlation tests. It was concluded that their concentration levels were independent of intra-seasonal changes. The likely natural and artificial sources of contaminants are run-offs from fertilized lands, septic tanks, industrial discharges, sewage and waste disposal, algae blooms and erosion from natural deposits. The inherent risk is water-related diseases such as waterborne diseases, water-washed diseases, water-based diseases and diseases transmitted by water-related insect vectors. Water resources should be protected through proper sanitation systems, limiting of up-stream discharges, maintenance of wellheads, boiling and municipal water treatment plants. Educational advice should be given to the inhabitants on the dangers posed by continuous drinking of contaminated water. These measures will prevent disease outbreak and public health burden in the area.