PETROLEUM POTENTIAL QUANTITATIVE FORECAST OF DEEPLY-BURIED REGIONAL RESERVOIRS OF THE LOWER JURASSIC DEPOSITS WITHIN THE YENISEI-KHATANGA AND EASTERN GYDAN PETROLEUM REGIONS OF THE SIBERIAN SECTOR IN THE ARCTIC

The article presents the results of petroleum potential quantitative forecast of the Toarcian, Pliensbachian and Hettangian-Sinemurian regional reservoirs of Lower Jurassic deep-buried deposits within Yenisei-Khatanga and adjacent territories of the Gydan petroleum regions based on models of structure and reconstructed conditions of formation for each of the noted reservoirs and their components – permeable complexes and fluid seals, developed earlier by the authors of this article. Tectonic, lithological-facies and geochemical criteria for assessing the oil-and-gas bearing prospects of reservoirs are described. The methodology and the petroleum potential quantitative assessment results for regional reservoirs with attached maps of petroleum potential of each reservoir are considered. The structure of hydrocarbon resources (HC) is given: the distribution of initial total hydrocarbon resources by phase composition, regional reservoirs and oil and gas-bearing areas.

Analysis of Total Hydrocarbon Exceeding Standard in Oil Chromatogram of a 500kV Main Transformer

Oil chromatographic analysis is widely used in transformer fault diagnosis However, the problem of excessive total hydrocarbons in the oil chromatogram caused by the failure of the transformer submersible pump is different from the failure of the transformer body. Technicians need to be able to accurately identify these two types of failure. For this problem, this article proposes a method of judging by manually starting and stopping the submersible pump and monitoring the change law of the transformer chromatographic data. This article first finds out suspicious submersible pumps through current data. Subsequently, the operator starts and stops the submersible pump and monitors the change law of the transformer chromatographic data. From this, the correlation between the start or stop of the submersible pump and the chromatographic data was found. Finally, the effectiveness of this method is verified by the submersible pump disassembly inspection and simulated live test.

Physicochemical properties, total hydrocarbon content, and trace metals of water and sediments from major River Estuaries within the Niger Delta Region of Nigeria

Water and sediment samples from Cross River, Imo River, and Qua Iboe River Estuaries were collected and treated using standard analytical procedures. The samples were analyzed for their physicochemical properties, total hydrocarbon content (THC), and trace metals. Results obtained revealed that, the mean levels of total suspended solids (TSS), total dissolved solids (TDS), turbidity, colour, biochemical oxygen demand (BOD), THC, cadmium (Cd), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn) in water were higher than their acceptable limits in Nigeria. Whereas, the mean levels water pH, electrical conductivity (EC), dissolved oxygen (DO), nitrate, sulphate, phosphate, and copper (Cu) were within their acceptable limits. The results obtained also revealed that, the mean levels of nitrate, THC, and Fe in sediments were higher than their recommended limits. While the levels of pH, EC, sulphate, phosphate, Cd, Cu, Ni, Pb, and Zn in sediments were within their recommended limits. This study indicated that the anthropogenic activities by oil and oil-related companies within the Niger Delta Region of Nigeria may have contributed significantly to the high level of toxic substances in the water channels within the zone. The results obtained revealed that, the direct or indirect exposure to untreated water from the studied water channels may result in serious health challenges. Hence, the environment should be closely monitored to forestall a devastating situation in the region.

Microbial Flora of Smoke-Dried Catfish (Clarias Gariepinus) Processed and Sold in Some Abattoirs in Bayelsa and Rivers States

The microflora of smoked catfish (Clarias gariepinus) sold in some abattoirs in Bayelsa and Rivers States were investigated. Smoked catfish samples were purchased within abattoirs and aseptically transported in ice-packed coolers to the laboratory. The total heterotrophic bacteria, total coliform, total hydrocarbon utilizing bacteria, total fungi and hydrocarbon utilizing fungal counts and identification of isolates from samples were analyzed using standard microbiological methods. Mean values of counts obtained showed that total heterotrophic bacteria ranged from 5.4 × 106CFU/g to 4.0 × 105CFU/g, total hydrocarbon utilizing bacteria ranged from 1.5 × 104 to 1.0 × 103CFU/g, total coliform ranged from 1.7 × 106CFU/g to 0, total fungi ranged from 4.3 × 104 CFU/g to 1.2 × 104CFU/g and total hydrocarbon utilizing fungi ranged from 3.5 × 103CFU/g to 1.1 × 103CFU/g. Kruskal Walis H test showed no significant differences (P≤0.05) in the total heterotrophic bacterial load nor in the total fungal load in the locations. Bacteria identified are Bacillus sp, Enterobacter sp, Escherichia coli, Micrococcus sp, Pseudomonas sp, Salmonella sp., and Shigella species. Bacillus sp, Pseudomonas sp and Micrococcus sp., were isolated in all the samples. Salmonella sp and Shigella sp occurred in Igbogene and Swale samples. Bacillus sp recorded the highest occurrence (34%) while Enterobacter sp. and Micrococcus sp recorded the least (7%). Bacteria with hydrocarbon utilizing potentials with percentage occurrence were Bacillus sp (70%) and Pseudomonas sp (30%). Fungi isolated were Aspergillus niger, A. flavus, Aspergillus fumigatus, Penicillium sp, Fusarium sp., and Rhizopus sp. Aspergillus species recorded the highest frequency (36.0%) while Rhizopus sp recorded the least (9.83%). Aspergillus niger, Fusarium sp and Penicillium sp were isolated from all the samples. Penicillium sp recorded hydrocarbon utilizing the potential and the highest percentage of occurrence (35.89%). The presence of a high microbial load of pathogenic bacteria and known mycotoxin producing fungi in the smoke-dried catfish are of great public health significance.

Capability of Vetiver (Vetiveria Zizanioides), Guinea Grass (Panicum Maximum) and Organic Manures to Remove Total Hydrocarbon and Heavy Metals from Crude Oil Contaminated Soil in Port Harcourt

In a field study conducted at the Teaching and Research Farm of Rivers State University PortHarcourt, Nigeria, to examine the ability of vetiver and guinea grasses amended with organic manures in remediation of crude oil polluted soil; soil polluted with Bonny light crude oil at 0 and 2% v/w was subjected to a remediation processes using vetiver (Vetiveria zizanioides) and Guinea grass (Panicum maximum) amended with organic manures for a period of twelve months. Two weeks after pollution, poultry and rabbit manures were applied at 0, 10, 20 and 30 tons per hectare respectively. Vetiver and guinea grasses were planted two weeks later. It was fitted in factorial split plots randomized block design. Results of the study revealed that remediation of the soil with grasses degraded the Total hydrocarbon content (THC) to 23 and 21.2% for vetiver and guinea grass respectively, while the quantity of heavy metals removed from the soil were 28.4% and 25.9% for iron, 37.3 and 32.8% for zinc, 35.8 and 30.8% for lead (Pb) and 23.1 and 38.5% cadmium for vetiver and guinea grass respectively. Amendment of the soil with 30 tons’ /ha organic manures increased the quantity of THC degraded to 70.6% and 67.9% for vetiver and guinea grass respectively while the concentration/quantity of heavy metals removed from the soil increased to 58.4 and 54.7% for Fe, 66.9 and 65.1% for Zn, 69.4 and 66.6% for Pb and 80.8 and 71.2%, in Cd for vetiver and guinea grass respectively. The quantity and concentration of THC and heavy metals degraded in the soil was higher in vetiver than guinea grass plots and in vetiver amended with poultry manure than in guinea grass amended with rabbit manure. There was a significant (P<0.05) difference in uptake of THC and heavy metals in plant tissues between vetiver and guinea grass. Vetiver accumulated more of the contaminants in their tissues than guinea grass. Amendment of the soil with organic manures reduced the uptake of the contaminants (THC and heavy metals) from the plant tissues. Generally, both grasses have the capability to remediate crude oil contaminated soil. Augmentation of the two grasses with organic manures enhanced their capability.

Evaluation of Heavy Metals and Total Hydrocarbon Concentration in the Qua Iboe River Estuary, Akwa Ibom State, Nigeria

The research assessed the concentration level of heavy metals and total hydrocarbon in Qua Iboe River Estuary of Akwa Ibom State, Nigeria during the months of April, May and June. The experimental research design was adopted and a total of 72 water samples were collected on weekly basis from ST1, ST2 and ST3 during high and low tides in thoroughly-rinsed 1-litre plastic containers to avoid adulteration of the samples. Samples were analyzed in-situ and in the laboratory using standard methods. The results of the concentrations of the sampled parameters during high tide included: Cr (0.003-0.21mgl-1), Fe (0.123-0.511mgl-1); Mn (0.018-0.66mgl-1), Pb (0.105-0.603mgl-1), Mg (0.42-0.623mgl-1), Cu (0.00-0.32mgl-1) and THC (0.12-0.88mgl-1)while the low tide concentrations showed: Cr (0.001-0.061mgl-1), Fe (0.56-4.11mgl-1), Mn (0.002-0.13mgl-1), Pb (0.011-0.211mgl-1), Mg (0.108-1.342mgl-1), Cu (0.011-0.076mgl-1) and THC (0.23-0.80mgl-1). The concentrations of Hg and As were negligible throughout the study. Analysis revealed that THC varied significantly across the sampled stations (ANOVA, P <0.001). Pollution Index, PI <1 for Ni, Mn, Na, Hg, As, Mg and Cu, implied that there was no pollution in the estuary. Fe showed that the estuary was slightly polluted with PI 1-2; Cr, V and THC recorded PI 2-3 signifying that the water was moderately polluted; PI >5 for Pb revealed that the estuary was seriously polluted with lead. The oil spills by ExxonMobil’s offshore platforms in the area, the heinous practices of waste dumping along the coast have resulted in the high THC and heavy metals concentrations found in the water samples. Hence, the water in Qua Iboe River Estuary is polluted and not safe for personal or domestic uses. The study recommended that Exxon Mobil and other oil companies in Nigeria should adhere strictly to international best practices in oil exploration/exploitation, environmental conservation, maintenance of equipment and safety of their infrastructure should be their priority. Prompt actions should be taken towards clean-up exercises in case of oil spill incidents in the area and proper, modern sewage and solid wastes disposal mechanism should be put in place by the host communities. Received: 31 January 2021 / Accepted: 27 February 2021 / Published: 7 March 2021

Treatment of Oil Wastewater Containing High Salinity with Ultrafıltratıon (UF) and Reverse Osmosıs (RO)

The high salinity oil wastewaters contained high salt, chloride, total hydrocarbon concentrations with COD and TSS. In order to treat this wastewater a sequential UF and RO ractor system was used. Before membrane treatment the oil was floated with an API oil separator. The effects of increasing fluxes ( 12 L/h, 30 L/h and 50 l /h) and pressures (4 bar , 8 bar and 16 bar ) on the removals of pollutant parametres were studied in the UF. The influence of the main operating parameters suh as operating pressure (15, 35 and 50 bar), temperature (25, 40 and 55 °C) and feed flowrate (7, 14, 28 L/min, were studied in RO. The maximum salt , chloride, total hydrocarbon, COD,dis-COD, and TSS yields were 90%, 91%, 89%, 89%, 89% and 90%, respectively, at a flux of 60 L/m2.h and at a pressure of 16 bar in UF, respectively. The maximum RO yields in the permeate were around 99% for the pollutant parameters given above at afed flowrate of 28 L/min at 24 bar pressure.

Enhancement of the soil quality of an oil-polluted ultisol using livestock wastes

The study investigated the enhancement of soil quality of an oil-polluted ultisol using livestock wastes. Top soil (0 - 10 cm) was obtained as a pooled sample and polluted with spent lubricating oil at 10% w/w. The soil was subsequently amended with sun-dried goat (GT), rabbit (RB), and poultry (PG) dung at 10% w/w on dry weight basis both in singles, double-mixed, and triple-mixed combinations. Twelve weeks after treatment application, results showed that there was a 93.9% decrease (p<0.05) in bacterial colony count in the oil-polluted soil compared to the control. Penicillium notatum and Aspergillus niger as well as Bacillus sp. and Proteus sp. were the prominent fungal and bacterial species identified respectively. The most abundant plant in the soil seed bank was Panicum maximum with 10.4% abundance and this showed possible involvement of the plant in remediation of oil-pollution. The total hydrocarbon content of the oil-polluted soil was 9984.0 mg/kg, compared to 3170.6 mg/kg when amended with RB+GT, implying 76.77% remediation efficiency. Among several trials employed in this study, the combination of rabbit and goat wastes proved to be more effective in reducing the total hydrocarbon content of oil-polluted soil and therefore, is recommended as a potential candidate for application in the bioremediation of such soil.