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African Journal of Engineering and Environment Research (AJOEER)

Journal Papers (28) Details Call for Paper Manuscript submission Publication Ethics Contact Authors' Guide Line
1 The Influence of Rescheduled-Overhaul in determining the number of Gas turbine Usage in Natural Gas Pipeline Transportation Network , Aziaka D. S1*; Le-ol A. K2; Pilidis P3.
Gas turbines are an integral part of the supply of natural gas in many parts of the world. In compressor stations, they are used for transporting gas from producing wells to consumers and across extensive networks of pipelines. This paper present how rescheduling of gas turbine overhaul from the baseline condition amid degradation influences the number of the gas turbine to be used in a compressor station without altering the original pipeline design for the desired amount of gas delivery. Eighteen compressor stations with gas turbine engines as the driver to the gas compressor have been investigated. The selected engines models were developed based on public domain specification, using an in-house engine performance simulation software: TURBOMATCH. Three seasons (rainy, dry and hot seasons) were considered in this paper based on the location of Trans-Saharan gas pipeline being investigated. Compressor and turbine were degraded (fouled) as a single type of degradation producing three performance scenarios (optimistic, medium and pessimistic). These scenarios define the levels of deterioration of the gas turbine in comparison with the clean conditions. The baseline case indicated that at a controlled TET, the number of GT used in each compressor station increases with increase in degradation (reduction in flow capacity and isentropic efficiency) which result to a variation in the number of engines per station. The result revealed that the implementation of rescheduled-overhaul on the engines reduces the number of Gas turbine usage at the same degraded and ambient condition of the baseline case. The further result indicated that the optimistic, medium and pessimistic scenarios that used 99, 106 and 120 number of engines for the 18 compression stations at baseline condition reduces to 91, 104 and 115 respectively when rescheduled overhaul was implemented for the same amount of gas to be delivered and at the same operating conditions. The proposed approach will enhance engine life-extension strategies that engine life-cycle managers, or natural gas pipeline investors may adopt to cost-effectively manage their engines while ensuring reliability and safety on the pipeline business. Keywords: Turbine Entry Temperature, Gas Compressor, TURBOMATCH, Natural gas, Degradation    
2 An Assessment of the Causes of Wellbore Instability and Stuck Pipe Occurrences in an Offshore Field, Niger Delta, Nigeria , Mode Ayonma W., Onuigbo Chukwuka, Anyiam Okwudiri, Eradiri J. N., Okeugo Chukwudike, and Umeadi Ijeoma  
Wellbore instability and consequential stuck pipe issues are a common challenge associated with offshore drilling. Usually, the effect of wellbore instability is an increase in non-productive time, possible loss of tools and costly drilling operations. Hence, there is a need for wellbore stability analyses before and during drilling operations. In “Agaza Field”, offshore Niger Delta, wellbore instability problems were encountered at various depths between 3,696-4,270 ft.; 5,000-5,425 ft. and 7,600-8000 ft. intervals. Sixty-five ditch-cutting samples and composite log plots obtained from both wells were and analyzed to determine the clay swelling potential and the cationic exchange between the formation and the drilling fluid as well as causes of formation instability. Agaza-1 well showed evidence of tight hole at intervals between 4,200 and 7,600 ft. In Agaza-2, there were indications of wellbore stresses from 1,908 ft. to 2,030 ft. However, deeper than 4,225ft depth, high fluctuation of pore pressure coincided with wellbore instability between 4,810 ft. and 5,200 ft. The principal clay minerals present within the formations are Illite, Smectite and Smectite/Illite interlayered types. Result of the cation exchange analysis showed that high concentration of calcium and sodium in the shale is responsible for high dissociation of the constituent minerals hence making the shales unstable. Analysis has shown that samples at some intervals from both wells are associated with high swelling potential while average cation exchange value is 40 meq/100g. Therefore, the primary cause of wellbore instability and stuck pipe within the studied intervals are attributed to high swelling and reactivity over time due to fluid-formation interaction.   Keywords: Clay cationic exchange, Clay swelling potential, Offshore drilling challenges, Reactive shales.  
3 The Inhibition Performance of Mono-Ethylene Glycol on Corrosion Rate of X-80 Grade Carbon Steel in Saturated Brine Environment.   , Ikeh, L and Dune, K.K  
The formation/deposition of hydrate and scale in gas production and transportation pipeline has continue to be a major challenge in the oil and gas industry. Pipeline transport is one of the most efficient, reliable and safer means of transporting petroleum products from the well sites to either the refineries or to the final destinations. Acetic acid (HAc), is formed in the formation water which also present in oil and gas production and transportation processes. Acetic acid aids corrosion in pipelines and in turn aids the formation and deposition of scales which may eventually choke off flow. Most times, Monethylene Glycol (MEG) is added into the pipeline as an antifreeze and anticorrosion agent. Some laboratory experiments have shown that the MEG needs to be separated from unwanted substance such as HAc that are present in the formation water to avoid critical conditions in the pipeline. Internal pipeline corrosion slows and decreases the production of oil and gas when associated with free water and reacts with CO2 and organic acid by lowering the integrity of the pipe. In this study, the effect of Mono-Ethylene Glycol (MEG) and Acetic acid (HAc) on the corrosion rate of X-80 grade carbon steel in CO2 saturated brine were evaluated at 25oC and 80oC using 3.5% NaCl solution in a semi-circulation flow loop set up. Weight loss and electrochemical measurements using the linear polarization resistance (LPR) and electrochemical impedance spectroscope (EIS) were used in measuring the corrosion rate as a function of HAc and MEG concentrations. The results obtained so far shows an average corrosion rate increases from 0.5 to 1.8 mm/yr at 25oC, and from 1.2 to 3.5 mm/yr at 80oC in the presence of HAc. However, there are decrease in corrosion rate from 1.8 to 0.95 mm/yr and from 3.5 to 1.6mm/yr respectively at 25oC and 80oC on addition of 20% and 80%  MEG concentrations to the solution. It is also noted that the charge transfer with the electrochemical measurements (EIS) results is the main corrosion controlling mechanism under the test conditions. The higher temperature led to faster film dissolution and higher corrosion rate in the presence of HAc. The EIS results also indicate that the charge transfer controlled behaviour was as a result of iron carbonate layer accelerated by the addition of different concentrations of MEG to the system.   Key words: CO2 corrosion, Carbon steel, MEG, HAc, Inhibition, Environment.  
4 Wear analysis of CNT-AL Nanocomposites using surface response method   , Umma Abdullahi, M.A. Maleque, M.Y. Ali and I.I. Yaacob 
Carbon nanotube (CNT) reinforced aluminium (Al) nano-composites were produced using powder metallurgy route with different weight percent of CNT in to the Al matrix. The wear behaviour of CNT-Al nano-composite  was studied using a pin-on-disc tribometer against AISI4340 steel disc. Experiments were conducted using different sliding velocities of 0.5, 0.65 and 0.8 m/s and a normal load of 5, 7.5 and 10 N. Design Expert (DOE) version 6.0.8 was used to optimize the process variable for wear and friction test of the developed CNT-Al nano-composite using face centered central composite design based on response surface methodology and confirmed that 1.5 wt% was the optimum CNT-Al nano-composite formulations. The result showed that higher hardness value of the material showed a lesser wear rate and better wear resistance. The result showed that the wear rate of the developed nano-composite decreased with the increasing of CNT content but up to 1.5 wt% CNT into the nano-composite. The wear rate values varied from 2-0.6 x10-3 mm3/m (2, 0.2, 0.17. 0.3 and 0.6 mm3/m x10-3 for 0 wt%, 1 wt%, 1.5 wt%, 2 wt% and 2.5 wt% CNT respectively). These results also showed that the rate of wear decreases with the increase in normal load and sliding speed. DOE confirm the accuracy of the experimental result for the evaluation of the developed CNT-Al nano-composite.   Keywords: Wear testing, Sliding wear, Wear modelling, Metal-matrix composite and CNT-Al nano-composite  
5 Evaluating the Effect of Mud Rheology and Cuttings Size on Cuttings Transportation in Vertical Wells   , Chukwu A. Godwin,  Kpea-ue Marvin Lezor, Kinate Bright  
As drilling optimization becomes the major concern of the drilling engineer and the mud specialist, there is therefore need to properly evaluate key success factors that ultimately affects the success of drilling operations. This research work examined the effects of fluid rheology and cuttings size on cuttings transportation in vertical wells. To achieve that, an experiment was conducted on two samples of fresh oil-based mud (A and B) of different rheology and two drilled cuttings sample (A and B) of sizes 400µm and 1000µm obtained from Anieze North field after sieve analysis. The drilled cuttings samples(A and B) were comingled with the mud(A and B) and their rheology (viscosity, density, plastic viscosity, yield point and gel strength) and cuttings transport parameters (slip velocity, transport velocity, transport ratio and transport efficiency) were checked at different temperatures. The cuttings transport parameters generated with the test models (Moore, Chien et al, and Zeidler) reveal that drilled cuttings of smaller size are easily transported than those of larger size. It was also observed that temperature has remarkable effects on rheology and slip velocity. Hence, slip velocity increases with temperature, while rheological values decrease with temperature. As a recommendation arising from the results of this investigation, a lower cuttings size should be ensured in a low viscous fluid for an efficient hole-cleaning. Apart from the aforementioned factors for efficient transportation of drilled cuttings, drilling bit configuration which is major determinant of the size of cuttings should be properly examined before selection for any drilling operation.   Keywords: Cuttings Size, Cuttings Transport, Mud Rheology, Slip Velocity, Temperature
6 Developing an Integrated Nuclear Waste Management Strategy on Aggregate Orphan Source Radioactive Materials in the Oil and Gas Sector.   , Neeka, J.B, Gabriel, O.E, Doosu, P.N. and Chizoba, O.F  
Orphan sourced radioactive waste materials associated with oil and gas exploration, exploitation and production have been identified as causal factors in environmental health risks of operation personnel and the host communities in the Niger Delta. These Technologically Enhanced Radionuclides such as 14C, 40K, 87Rb, 232Th, 288U and some low frequency radioactive heavy metals constitute potential dangers to environmental health assay. Highly Sensitive Radiation Detection Tracers (HSRDT) were deployed for tracking and analysis of ionized leakages in the coastal marine offshore and shallow offshore areas in in a typical deltaic region.  The inverse determination technique of the generalized half-life period was integrated into the model equations 1 – 12. Table 1 is a survey from 1992 t0 2015, showing that some identified radionuclides are reactive and contaminants to the surrounding environment from oil and gas processes. However, inadequate strategic decommissioning activities are responsible for severe occupational and environmental hazards to flora and fauna. This paper is fundamental to developing an integrated orphan waste management system as remedial techniques to minimize radiation waste burns and other harmful environmental effects on personnel and the environment. Its application is useful for decision-making on radioactive waste material management strategy. Furthermore, possible conceptual legal framework and standards for the disposal system of orphan sourced radionuclides in the petroleum sector could be explored.   Keywords: Radioactive Waste Materials; Aggregate Orphan–Sourced Radionuclides; Environment Management; Waste Disposal Systems; Oil and Gas Sector etc.
7 Experimental Production of Biofuel using Lactose as an Enhancer to Aspergillus Niger and Saccharomyces Cerevisae   , M. N. Idris and M. M. Usman  
Nigeria is a rich nation in natural resources, which includes source of biofuel such as sweet potato starch etc. This starch can be converted to sugar through hydrolysis process in other to yield ethanol (biofuel). In this research work, the sweet potato peels was selected as a substrate for bioethanol production in the process, as it is rich in starch and cellulose. In this study, 5g, 10g, 15g, 20g and 25g each was weighed lactose and added to the Aspergillus Niger and Saccharomyces Cerevisae, the highest yield recorded when 20g of lactose was introduced. This achievement was observed after seven days, and the concentration of 91 ppm was highest for the sample containing 25g of lactose. The study also revealed that when lactose was added to fermentation medium together with  enzyme Aspergillus Niger, the results obtained show that the 20g lactose represent a highest yield of biofuel production. In summary, the increase and subsequent decrease in pH and specific gravity of each fermented sample indicated that the reaction (fermentation) was actually occurred, that is, the conversion of the substrate to products as well as the release of CO2 as the by-product took place.   Keywords: Aspergillus Niger, biofuel, starch and cellulose
8 Dilute Caustic and Water Comparisons as Solvents in the Removal of Acidic Gases from Combustion exhaust Stream of a Boiler. , Harry-Ngei, N. and Edward, P. A
This work focused on the comparative analyses between the use of dilute caustic with a composition of 1.84% and using water alone (pH=7) that have the potential to remove SO2 completely from the exhaust flue gas of a combustion system and H2S in the incomplete reaction scenario. Two reaction pathways were utilized for the study, the complete combustion pathway as well as the incomplete combustion pathway. ASPEN HYSYS 8.6, a process simulation software, was used to simulate conditions with PENG-ROBINSON utilized as the vapour-liquid equilibrium (VLE) data prediction tool of the software. For the complete combustion pathway, a complete removal of SO2 was achieved using caustic while with the same conditions, utilizing water as solvent achieved a reduction of 90%. For the incomplete combustion pathway, using caustic gave about 53% removal efficiency for H2S while the water only showed a poor 16% increase of H2S. The study recommended the use of the dilute caustic for the following reasons; it gave a better removal percentage than using water alone, the use of the caustic will not contribute to caustic corrosion because of the low composition of the dilute caustic that will be used in the absorber, the choice of the caustic was also observed to be economical. Keywords: Caustic, Absorption, Emission, Simulation, Combustion, Solvents.
9 Prediction of Condensate Banking with Relative Permeability To Oil – Gas And Saturation In A Gas Condensate Reservoir. , Minimah, M. D, Ifeanyi, S. N, and Bright B. K
Gas condensate fields are quite lucrative fields because of the highly economic value of condensates. However, the development of these fields is often difficult due to retrograde condensation resulting to condensate banking in the immediate vicinity of the wellbore. In many cases, adequate characterization and prediction of condensate banks are often difficult leading to poor technical decisions in the management of such fields. This study will present a simulation performed with Eclipse300 compositional simulator on a gas condensate reservoir with three case study wells- a gas injector (INJ1) and two producers (PROD1 and PROD2) to predict condensate banking. Rock and fluid properties at laboratory condition were simulated to reservoir conditions and a comparative method of analysis was used to efficiently diagnose the presence of condensate banks in the affected grid-blocks. Relative Permeability to Condensate and gas and saturation curves shows condensate banks region. The result shows that PROD2 was greatly affected by condensate banking while PROD1 remained unaffected during the investigation. Other factors were analyzed and the results reveal that the nature and composition of condensates can significantly affect condensate banking in the immediate vicinity of the wellbore. Also, it was observed that efficient production from condensate reservoir requires the pressure to be kept above dew point pressure so as to minimize the effect and the tendency of retrograde condensation.   Keywords: Condensate Banking, Phase Production, Relative Permeability, Relative Saturation, Retrograde Condensation
10 Geochemical and Geostatistical Assessment of Cretaceous Coals and Shales in some Nigerian Sedimentary Basins for their Hydrocarbon Proness and Maturity levels. , Obaje, N. G. , Adamu, L. M., Umar, U. M. , Umaru, A. O., and Okafor P, N.
The Rock–Eval pyrolysis and LECO analysis for 9 shale and 12 coal samples, as well as, geostatistical analysis have been used to investigate source rock characteristics, correlation between the assessed parameters (QI, BI, S1, S2, S3, HI, S1 + S2, OI, PI, TOC) and the impact of changes in the Tmax on the assessed parameters in the Cretaceous Sokoto, Anambra Basins and Middle Benue Trough of northwestern, southeastern and northcentral Nigeria respectively. The geochemical results point that about 97% of the samples have TOC values greater than the minimum limit value (0.5 wt %) required to induce hydrocarbon generation from source rocks. Meanwhile, the Dukamaje and Taloka shales and Lafia/Obi coal are found to be fair to good source rock for oil generation with slightly higher thermal maturation. The source rocks are generally immature through sub-mature to marginal mature with respect to the oil and gas window, while the potential source rocks from the Anambra Basin are generally sub-mature grading to mature within the oil window. The analyzed data were approached statistically to find some relations such as factors, and clusters concerning the examination of the source rocks. These factors were categorized into type of organic matter and organic richness, thermal maturity and hydrocarbon potency. In addendum, cluster analysis separated the source rocks in the study area into two groups. The source rocks characterized by HI >240 (mg/g), TOC from 58.89 to 66.43 wt %, S1 from 2.01 to 2.54 (mg/g) and S2 from 148.94 to 162.52 (mg/g) indicating good to excellent source rocks with kerogen of type II and type III and are capable of generating oil and gas. Followed by the Source rocks characterized by HI <240 (mg/g), TOC from 0.94 to 36.12 wt%, S1 from 0.14 to 0.72 (mg/g) and S2 from 0.14 to 20.38 (mg/g) indicating poor to good source rocks with kerogen of type III and are capable of generating gas. Howeverr, Pearson’s correlation coefficient and linear regression analysis shows a significant positive correlation between TOC and S1, S2 and HI and no correlation between TOC and Tmax, highly negative correlation between TOC and OI and no correlation between Tmax and HI.   Keywords- Cretaceous, Geochemical, Statistical, Cluster, Factor analyses.
11 Use of Sugarcane Rind Activated Carbon For Removal Of Organic Content In Wastewater. , Nyam, T.T.; Nwosibe, P.O.; Atiwurcha, N. I and Okechukwu, J. O
In this study, activated carbon produced from sugarcane rind was used to treat synthesized wastewater for the removal of formaldehyde. The prepared precursor was impregnated with ZnCl2 before carbonization at 300℃ for 30 minutes. Proximate analysis of the produced activated carbon showed that it had a moisture content of 15.3 %, ash content of 5 %, and fixed carbon of 69.7 % amongst others. While BET analysis revealed the activated carbon has a surface area of 328.87 m2 and a pore diameter of 2.840e+00 nm. When used in batch process treatment of wastewater the activated carbon showed an 18 – 25 % adsorption efficiency in removal of formaldehyde from the wastewater. This shows that this sugarcane rind hitherto considered as waste and a pollutant has values to be explored.   Keywords: Activated carbon, Formaldehyde, organic content, wastewater, Sugarcane peels, Sugarcane Rind etc.
12 Adsorption Study of Particle Sizes of Maiganga Coal. , Umar, A. , Muhammad, I.M. , Funtua, M.A. and Mohammed, H.Y.
The main purpose of this work is to carry out adsorption study of different particle sizes of Activated Maiganga Coal. Activated carbon was produced from five different particle sizes of 63 μm, 300 μm, 425 μm, 600 μm and 2.0 mm from coal using potassium hydroxide as an activating agent. Freundlich and Langmuir adsorption kinetics as well as some quality parameters were studied for the produced activated carbon. These quality parameters were evaluated for the five different samples. With the gradual increase in PH values from 5.7 to 8.3, a corresponding decrease in uptake has been observed as a result of deprotonation of the adsorbent surface. The ash content was found to increases as the particle sizes increases. The n values which reflects the intensity of adsorption decreased from 0.573 to 0.061. The K values (Freundlich constant) present the opposite trend which increased from 69.984 to 163.682. The magnitude of Qo which indicates the amount of phosphate per unit weight of the adsorbent to form a complete monolayer on the surface also increased from 0.05 to 0.50. This work shows that, the finer the particle size of activated carbon, the greater the adsorption capabilities. Keywords: Activated Carbon, adsorption, Coal, Freundlich, Langmuir, Maiganga,
13 Advances on the Geology and Evaluation of Potential Petroleum Systems of the Sokoto Basin in NW Nigeria. , Obaje, N. G., Faruq, U. Z. , Bomai, A. , Moses, S. D. , Ali, M. S. , Adamu, S. , Essien, A. , Lamorde, U. , Umar, U. M. , Ozoji, T. , Okonkwo, T. P. , Adamu, L. , Idris-Nda, A.
The stratigraphy of the Sokoto Basin has the Illo/Gundumi Formation at the bottom, followed successively upward by the Taloka, Dukamaje, Wurno, Dange, Kalambaina, Gamba and Gwandu Formations. Re-mapping of the basin carried out in this study shows that the geological framework remains largely as previously outlined except that some hitherto unreported tectonically controlled structures have been documented. The basin is generally shallower at the margin and deepens towards the centre such that the areas around the border with Niger Republic are deepest and hence most prospective on the Nigerian side. Geophysical aeromagnetic interpretation has assisted to analyze the depth to basement configurations. Organic geochemical studies show that the dark shales and limestones of the Dukamaje Formation constitute the source rocks in the potential petroleum system. With averages for source rock thickness of 50m, area of basin of 60,000km2, TOC of 7.5wt%, and HI of 212mgHC/gTOC, charge modeling indicates 808.10 million barrels of oil equivalent extractable hydrocarbons in the Sokoto Basin, at current knowledge of the geology and if the appropriate maturity has been attained at deeper sections. The sandstones of the Illo/Gundumi Formation as well as in the Taloka and Wurno Formations and carbonates of the Kalambaina Formation provide potential reservoir packages. The paper shale of the Gamba Formation and the clays of the Gwandu Formation provide regional seals. If the presently mapped tectonic structures are ubiquitous in the whole basin, structural and stratigraphic traps may upgrade the petroleum system. Other petroleum systems may exist in the basin with either or both the Illo/Gundumi and Taloka Formation(s) providing the source and reservoir rocks.   Keywords: Sokoto Basin, Dukamaje Formation, Hydrocarbons, Petroleum System, Reservoirs
14 An Experimental Investigation of the Effects of Cuttings Size on Mud Rheology. , Chukwu A. G, Kpea-ue M. L, and Nwankwo I. S.
Effective hole-cleaning is vital for a successful drilling operation and has significant effect on optimizing factors such as penetration rate, bit optimization and well stability. Efficient transportation of drilling cuttings are dependent on factors such as fluid properties and rheology, cuttings size and shape, fluid velocity, cuttings concentration, cuttings transport velocity and rate of penetration. This experimental work examined the effects of cutting sizes on drilling fluid rheology. To achieve this, two fresh samples of mud were prepared and the rheological properties were analyzed at different temperature ranges representing the operating conditions of most Niger Delta wells. A mesh analysis was carried on dried fresh drill cuttings from the Anieze North Field and dried cuttings taken from the laboratory and two samples were selected at ASTM#40 and #18. 10 % of these cuttings’ samples were added to each mud sample and the rheological properties were measured at similar temperature ranges as the original mud samples. The results gotten shows that at the various temperature ranges, mud contamination with smaller drill cuttings size (ASTM #40=400um) showed a better performance than the larger particles. The mud rheological properties (viscosity, yield point, YP, plastic viscosity, PV and density) measured at different temperatures showed a remarkable non-linear behavior as shown in the results.   KEY WORDS: Cuttings Size, Drill Cuttings, Mud Contamination, Mud Rheology, Temperature.
15 Absorber Performance Improvement Through Solvent Concentration Changes to Regulate Emissions from Combustion Systems. , Harry-ngei, ngei
This work highlighted the determination of the best concentration profile for the operation of an absorber with potential to cut down combustion products emissions from the complete combustion reaction scheme of a combustion system waste stream. The proposed solvent concentration had a range of 1.84%-2.20% of caustic entrainment, therefore further increase on the solvent concentration above 2.20% is not feasible. Incremental changes of 0.06% were made to assess the optimal concentration required for best absorber performance. A process simulation software, ASPEN HYSYS 8.6, was utilized to simulate the emissions profile with PENG-ROBINSON as the Vapour-Liquid Equilibrium evaluation tool in the software. The study found the performance of the absorber improved with a corresponding increase in the concentration with 2.20% giving the most efficient removal rate of 61.59%, 26.5% and 85.2% for SO2, CO2 and NO2, respectively. The study recommended that one veritable method of improving the performance of absorber systems is to increase the concentration of the alkali-based solvent to cut down on emissions from flue gas systems.   Keywords:Absorber Performance, Solvent Concentration, Combustion Systems, Vapour-Liquid Equilibrium and Flue Gas Systems.
16 Geology and mineral resources of Ebonyi State, southeastern Nigeria. , Friday D, O ; Betram M, O; and Chijiuka O.
Ebonyi State is underlain at depth by the Precambrian Basement Complex and by Cretaceous sedimentary units which include the Abakaliki Formation, Nkalagu Limestone, Amasiri Sandstone and Afikpo Sandstone and spans through Southern Benue Trough and Anambra Basin. Shales, sandstones, siltstones and limestones which range from shallow to deep marine depositional environments have intermediate to basic intrusive dolerites, extrusives and pyroclastics rocks emplaced in them. The sediments are dominated by physical structures such as faults, folds, fractures, joints, cross beds, mud cracks and an unconformity; chemical structures such as concretions and solution cavity; and biogenic structures such as burrows and bioturbation. The presence of benthic foraminifera such as Bolivina anambra and Haplopragmoides sp. suggest an upper bethyal deep to shallow marine environment for the sediments. Natural resources and mineral deposits such as lead, zinc, granite, limestone, dolerite, pyroclastics, salt-lake/brine, sand, laterites, clay, kaolin, iron ores, chalcopyrite, illmenite, fluorite, marble stone, quartz and copper ore which spread across the area, contribute largely to the gross domestic products of the state. Data gathered shows that 26% of the mineral deposits are partially exploited, 30 % are locally exploited, 4 % are highly exploited, while 39 % are dormant. Unfortunately, the reserve estimate of these mineral deposits are yet to be documented.   Keywords: Anambra Basin, Ebonyi State, Mineral deposits, Southern Benue Trough, Structure; Uncomformity
17 Preliminary Investigation of the Chemical Composition of Ballast Water and Tank Sediments of Selected Ships within the Lagos Harbour, Nigeria. , Bamanga, A, Bassey, B and Al-Anzi, B
Ballast water is important for safe and efficient operation of vessels, helping to maintain stability during voyage in seas and docking in harbours. However, ballast water can pose considerable environmental challenges because they are often laden with polluted sediments and invasive species. The Lagos Harbour, which houses in the largest port in West Africa, receives about five thousand vessels annually which discharge ballast water and tank sediments into the water with the potential to cause environmental pollution. In the Nigerian context there is high potential for pollution due to weak regulations, poor enforcement and limited research of this kind in order to understand their composition, fate and impacts. This study aims at characterizing the chemical composition (Heavy metals- Arsenic, Cadmium, Chromium, Copper, Lead & Zinc, as well as carbon and nitrogen content) of the ballast water and the tank sediments because of their positive correlation with the survival of invasive species in the ballast water and tank sediments. Water samples were collected from four ships (2 cargos and 2 tankers) within the Lagos Harbour; surface (1-5 cm) sediment samples were scooped from ship tanks using a specialized grab for sampling ballast sediments. The sediments were transferred in specialized sample containers (cool boxes) to the University of Portsmouth in United Kingdom for analysis. Total metal concentrations were analysed using X-ray fluorescence (XRF). They were subjected to two acid digestions: Aqua regia (AR) and 1 M hydrochloric acid (1 M HCl) following the procedures set out by the Canadian National Water Research Institute (NWRI) and the United States Environment Protection Agency (US-EPA Method 3050B). Total carbon and nitrogen contents were determined using an in-line Yanaco MT-5 CHN analyser. The results obtained were compared with established guidelines and subjected to correlation and Principal Component Analysis (PCA). The findings indicated high concentrations of Nickel, Lead, and Zinc in the sediments with values of 59.6 mg/kg, 33.75 mg/kg and 43,145.7 mg/kg respectively which exceeded NOAA and CSQGs permissible standards. Tanker vessels contained relatively higher concentrations of the pollutants than cargo vessels. The findings from this study provide useful baseline data which will guide a more intensive investigation of the chemical composition of ballast water and tank sediments for effective comparison with what is obtainable elsewhere in the world. The maritime industry needs to pay close attention to ballast as a potential source of marine pollution particularly in developing countries like Nigeria where there is limited regulation for management of coastal areas with respect to shipping activities. The IMO needs to direct further effort at investigating the non-biological components of ballast water and sediments in order to protect valuable biodiversity.   Keywords: Coastal Pollution, Ballast Water Management, Ships, Analytical Techniques
18 Effect of Biomass Blending and Desulphurization on Flue Gas Emissions of Nigerian Sub Bituminous Coal Briquettes.  , Adekunle, J.O, Ibrahim, H. D and Ibrahim, J.S.
The effect of blending, briquetting and desulphurization of coal and biocoal briquettes of Nigerian sub bituminous coal is discussed. The flue gas of the coal and biocoal samples were analyzed to study the emission characteristics of nitrogen oxide (NO2), sulphur dioxide (SO2) and carbon monoxide (CO) due to environment concern with the use of coal as either domestic   or industrial fuel. Sub bituminous coal sample from eight coal mines and sites in five states in   Nigeria were collected. The states and sites included Kogi (Ogboyoga, Okaba), Benue(Owukpa),Nassarawa (Lafia/Obi), Ebonyi (Afikpo) and Enugu (Okpara,Onyeama and Ezinmo).The samples were pulverized and blended with sawdust at various constituent ratios of 0:100, 10:90, 20:80, 30:70, 40:60, 50:50 and 100:0 sawdust : coal. Cassava starch was used as binding material while calcium hydroxide was used as desulphurizing agent for the briquettes. Emission tests for various compositions of the briquettes were carried out and the O2, CO2, CO, NO2 and SO2 of the briquettes were compared. Results showed reduction in combustion emission withincrease in sawdust concentration with the reduction in smoke and noxious gas emission. Thesulphur dioxide range of the coal briquettes is between 0.018ppm and 0.028ppm which decreased to between 0.025and 0.005 ppm in biocoal briquettes. Same for nitrogen oxide which range between 0.034ppm and 0.038ppm but decreased to between 0.025 and 0.019 ppm and carbon    monoxide range of between 0.3ppm and 0.48ppm which decreased to between 0.43ppm and 0.12 ppm in the biocoal briquettes. The 50:50 blends of sawdust to coal for Ogboyaga has the lowest carbon monoxide emission of 0.12 ppm; Okpara has the lowest sulphur dioxide emission of 0.005ppm while Onyeama has the lowest nitrogen oxide emission of 0.019 ppm. These are below the national ambient air quality standards which put sulphur dioxide at 1.4 x 10-1 ppm. The biocoal briquette emits less sulphur dioxide because it contains desulphurizing agent which fixes some of the sulphur that would have gone to the atmosphere to ash. Keywords: biocoal briquettes, blending, flue gas emissions, sub - bituminous coal.  
19 Effect of Biomass Blending and Desulphurization on Flue Gas Emissions of Nigerian Sub Bituminous Coal Briquettes.  , Adekunle, J.O, Ibrahim, H. D and Ibrahim, J.S.
The effect of blending, briquetting and desulphurization of coal and biocoal briquettes of Nigerian sub bituminous coal is discussed. The flue gas of the coal and biocoal samples were analyzed to study the emission characteristics of nitrogen oxide (NO2), sulphur dioxide (SO2) and carbon monoxide (CO) due to environment concern with the use of coal as either domestic   or industrial fuel. Sub bituminous coal sample from eight coal mines and sites in five states in   Nigeria were collected. The states and sites included Kogi (Ogboyoga, Okaba), Benue(Owukpa),Nassarawa (Lafia/Obi), Ebonyi (Afikpo) and Enugu (Okpara,Onyeama and Ezinmo).The samples were pulverized and blended with sawdust at various constituent ratios of 0:100, 10:90, 20:80, 30:70, 40:60, 50:50 and 100:0 sawdust : coal. Cassava starch was used as binding material while calcium hydroxide was used as desulphurizing agent for the briquettes. Emission tests for various compositions of the briquettes were carried out and the O2, CO2, CO, NO2 and SO2 of the briquettes were compared. Results showed reduction in combustion emission withincrease in sawdust concentration with the reduction in smoke and noxious gas emission. Thesulphur dioxide range of the coal briquettes is between 0.018ppm and 0.028ppm which decreased to between 0.025and 0.005 ppm in biocoal briquettes. Same for nitrogen oxide which range between 0.034ppm and 0.038ppm but decreased to between 0.025 and 0.019 ppm and carbon    monoxide range of between 0.3ppm and 0.48ppm which decreased to between 0.43ppm and 0.12 ppm in the biocoal briquettes. The 50:50 blends of sawdust to coal for Ogboyaga has the lowest carbon monoxide emission of 0.12 ppm; Okpara has the lowest sulphur dioxide emission of 0.005ppm while Onyeama has the lowest nitrogen oxide emission of 0.019 ppm. These are below the national ambient air quality standards which put sulphur dioxide at 1.4 x 10-1 ppm. The biocoal briquette emits less sulphur dioxide because it contains desulphurizing agent which fixes some of the sulphur that would have gone to the atmosphere to ash. Keywords: biocoal briquettes, blending, flue gas emissions, sub - bituminous coal.  
20 Ecological Risk Assessment and Pollution Load of Heavy Metals in Soils within Bori Urban, Rivers State, Nigeria.   , NWINEEWII, J.D. and NYODEE, G.T.  
The study assessed the ecological risk and polluting load of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in surface soils within Bori Urban. The composite soil samples collected from different locations were prepared and atomic absorption spectrophotometer (AAS) was used for the analysis of the heavy metals. From the results of the analysis, the mean concentrations (mg/kg) of the heavy metals decreased in the order Cu (37.42) > Ni (34.06) > Cr (28.66) > Zn (7.75) >Pb (2.03) > Cd (0.89). The mean concentrations of Cd, Cu, and Ni were above USEPA soil guidelines and world unpolluted soil average, while those of Pb and Zn were below. The mean concentrations of the heavy metals from the study locations were all above that of the control location. The findings indicated that the urban soils of the study were loaded with heavy metals due to anthropogenic activities. The anthropogenic percentage input was in the range of 63.92 - 89.13 above 50% indicating anthropogenic origin of the heavy metals in soils of the study area. The results of ecological risk index (Er) indicated that Cd with Er (467.40) contributed up to 94.51% to the potential ecological risk index (RI) while Zn (0.78) contributed 0.16%. The heavy metals under study posed highly strongly potential ecological risk with RI value of 494.56 to the Bori urban soil due to anthropogenic activities. The ANOVA result of FCal 6.42 > [F(5.30) = 2.53, P< 0.05)] revealed significant differences between the soil sample mean values due to different anthropogenic pollution sources with different loads of heavy metals as pollutants. The Omega Squared (w2) value of 0.52 > 0.14 showed very strong interactive relationship among the heavy metals to bring about high level of ecological potential risk of the urban soils in the study area. Based on the findings, the surface soils have elevated load of heavy metals thereby posing ecological potential risk to Bori urban soils. Therefore, there should be periodic monitoring and environmental audit by relevant authorities to ensure good soil quality of Bori urban soil. Keywords: Potential ecological risk, pollution load, Bori Urban, Anthropogenic Percentage input, contamination Factor.  
21 Comparative Study and Analysis of Carbon Steel Corrosion in co2 Saturated Environment.   , Ikeh L, Ezeike, K.C and Neeka, J.B  
Carbon steel is arguably one of the most efficient, reliable and safer kind of steel used in petroleum and gas industry for production, distribution and transmission of products. Acetic acid (HAc), is also one of the impurities in oil and gas during transportation from the well sites to the refineries. It is formed in the formation water, which also present in oil and gas production and transportation processes. Acetic acid aids corrosion in pipelines and as a result causes environmental degradation. It has been observed that high concentration of HAc increases the rate of corrosion of carbon steel in CO2 environment. Corrosion slows down production of oil and gas and thereby reduces revenue. In this work, a comparative study and analysis of carbon steel corrosion in the presence of HAc was carried out at 25oC and 80oC in CO2 saturated environment. Weight loss and surface analysis methods (XRD, EDX and SEM) were used to characterize the corrosion layers of the carbon steel samples at different conditions. The weight loss results show that the corrosion rate increased initially with the increase in the concentration of HAc and attained a maximum, and then gradually decreased. At 25oC with 500ppm of HAc, the corrosion rate is 1.35 mm/yr, and 1.80 mm/yr when 1000ppm of HAc was added to the solution. At 80oC and 500ppm HAc, the corrosion rate was 1.80 mm/yr and 2.70 mm/yr with 1000ppm of HAc. A further increase was observed at 3.45 mm/yr when 2500ppm of HAc was added to the system. This increase in corrosion rate is attributed to increase in temperature as increased temperature increases the rate of all reactions. The XRD analysis confirmed that the iron is formed in the absence of HAc while siderite (FeCO3), which is an ore of iron is observed on the materials with HAc. The SEM and EDX results confirmed that a fairly dense material of FeCO3 was formed in the absence of HAc and the layers became porous on addition of HAc to the solution. Key Words: Corrosion, Acetic acid, Carbon steel, CO2, Environment  
22 Chemical Composition and Antioxidant Activities of Beetroot Peel.   , Shuaibu B.S. , Aremu M. O. and Kalifa U. J.   
Proximate, mineral and antioxidant properties of beetroot (Beta vulgaris) peel were investigated using standard analytical techniques. Result for proximate revealed that moisture content was 30.88%, ash content (10.58%), crude fat (3.29%), crude fiber (6.98%), crude protein (4.10%) and carbohydrate (44.17%). The mineral composition (mg/g) also showed that sodium was 4.17%, iron (26.46%), copper (0.21%), magnesium (5.91%), potassium (13.82%) and phosphorus (11.57%) while zinc and calcium were not at detectable range of AAS. There was no activity for its antioxidant property. The results obtained from this analysis shows that Beetroot peel is a good source of carbohydrates, protein, ash, fiber, lipid and moisture, it also contained some mineral contents such as copper, phosphorous and iron which are required by the body to function effectively. Its consumption is therefore encouraged instead of regarding it as a waste material. Keywords: antioxidant, investigation, mineral, peel, proximate.  
23 Engineering Properties of Lateritic Soil in Otun Area, Ekiti State, Nigeria   , Obaro, R.I and Obaro, N.T  
Lateritic soils at Otun Ekiti, Ekiti state, southwestern Nigeria were investigated with respect to their geotechnical properties and their suitability for subgrade and sub – base construction materials. Four disturbed lateritic soil samples (sample A, B, C and D) were selected for the various laboratory techniques. The grain size analyses, the specific gravity tests, the atterberg limit tests, compaction, California bearing ratio and shear box tests were carried out on the samples. The grain size analysis shows that sample A is gravelly silt-clayey sand. Sample B is silt – clayey gravel composition. Sample C is gravelly silt-clayey while Sample D is silt-clayey gravel. Atterberg consistency limit test indicate that sample A has 30.0%, liquid limit 19.5% plastic limit, 10.5% plasticity index, 9.1% shrinkage limit. Sample B has liquid limit of 27.0%, 16.2% plastic limit, 10.8% plasticity index and 7.4% shrinkage limit. Sample C has a liquid limit of 32.4%, plastic limit of 15.6%. It has a plastic index of 16.8%, Shrinkage limit of 9.7% while Sample D has a liquid limit of 36.2%, plastic limit of 17.7%. It has a plastic index of 18.5% and 11.1% as shrinkage limit. Thus, the soil is classified to be intermediate plasticity which can be used for sub – grade and sub – base materials. The soil samples are above the activity (A) line in the zone of intermediate plasticity (CL) which suggests that they are inorganic soils. Based on engineering use chart, the workability as construction engineering is good to fair particularly as erosion resistance in canal construction. However, the high shrinkage limit may also reduce erosion in this area because of cohesion of the plastic clay material. The California Bearing Ratio (CBR) values are within 2 – 3% (mean = 2.75%) and 2 - 4% (mean = 2.75%) in sample A and sample B respectively while California Bearing Ratio (CBR) of 2 - 4% (mean = 2.75%) and 2 – 3% (mean = 2.75%) in sample C and sample D respectively. This implies that the materials can be used as a sub-grade to base course material for support of flexible pavements. The compaction tests for the optimum water content for sample A is 15.0% and 13.0% for standard and modified proctor respectively. The standard and modified proctor for sample B is 15.0% and 14.0% respectively. The compaction tests for the optimum water content for sample C and D is 15.0% and 14.0% for standard and modified proctor respectively. The compaction tests for Sample A indicate a higher fine fraction and thus a higher optimum moisture content while sample B, C and D has higher coarse fraction with lower optimum moisture content. The cohesion falls within 70-90Kpa (mean = 79Kpa) and the angle of internal friction ranges from 260 - 320 with mean of 280 for standard and modified compaction energies respectively. The results obtained from geotechnical analysis suggest that the soil is good to fair as erosion resistance in canal construction because of its high bearing capacity and it can also be used as sub – grade and base course in road construction. Keywords: Lateritic soil, Construction, Erosional and Geotechnical.  
24 The Role of Leadership in Tacit Knowledge Transfer in the Nigerian Oil and Gas Industry.     , Funminiyi S. Egbedoyin and Edward P. Agbai
The oil and gas industries are knowledge driven industry. The technology deployed in deep water exploration and production involve knowledge-intensive process by highly technical personnel. The problem was that the leadership of the oil and gas industries have not necessitated early recovery of tacit knowledge transfer from experts to employees managing the plant operations. The purpose of this qualitative multiple case study was to gain an understanding of how oil and gas industry leaders in Nigeria facilitate the transfer of tacit knowledge from experts to employees managing the plant after exploration activities. The conceptual framework was the socialization, externalization, combination, and internalization model developed by Nonaka and Takeuchi and Burns’ transformational leadership theory. A qualitative multiple case study design was used by adopting multiple sources of information including semi-structured interviews, field notes, and review of organizational documents. The unit of analysis was leaders in an oil and gas services organization. The data analysis processes involved coding of the data, categorizing the coded data, and subsequently generating themes in line with the research question using NVivo Version 12 software. Findings indicated that leaders facilitated the transfer of tacit knowledge through the creation of a safe working environment and demonstration of care for the employees. The opportunity to facilitate the transfer of tacit knowledge from expert to employees managing operations after exploration enhance the organization’s stability and promotes healthy communities. Keywords– Knowledge-Transfer, Leadership Style, Oil and Gas Industry  
25 HEAVY METALS CONTAMINATIONS IN SURFACE SOILS WITHIN BORI, RIVERS STATE, NIGERIA.     , NWINEEWII, J. D  
Heavy metal contaminations in surface soils within Bori were examined. The composite soil sample at 10 – 15cm depth was collected from each of the seven sampling locations including the control location using a stainless-steel hand auger. The soil samples were air-dried for 2 days, homogenized and sieved through a 2mm mesh to obtain uniform size. The soil samples were subjected to wet digestion method using nitric-perchloric acid. The digested samples were used for determination of concentrations of the heavy metals (Cd, Cr, Ni, Mn, Pb, Fe Cu and Zn) using the atomic absorption spectrophotometer (AAS).  The mean concentrations of the heavy metals obtained ranged as follows: Pb (0.553 – 4.551 mg/kg), Cr (1.713 – 7.965 mg/kg), Cd (0.011 – 2.549 mg/kg), Mn (6.914 – 40.162 mg/kg), Ni (2.942 – 6.597 mg/kg), Zn (4.468 – 13.976 mg/kg) and Cu (1.90 – 11.503 mg/kg). The results were below the world average values except Fe (53.554 – 122.203mg/kg). The enrichment factor values ranged between 0.04 and 20.86 and showed low to moderate enrichment due to anthropogenic activities. The pollution load index (PLI) value was 1, the combined pollution index (CPI) values ranged between 0.39 and 1.73 and the metal pollution load index (MPL) value of 3.73 > 1 revealed pollution in urban surface soils of the study area. The high positive correlation result among the heavy metals in the sample soils of the study area suggested that they are of similar pollution sources. Based on the findings, the urban surface soils of the study area are contaminated with heavy metals. Therefore, there should be monitoring and environmental audit by relevant authorities to ensure adequate environmental quality of urban surface soils in the study area.   Keywords: Heavy metals, contaminations, Bori, metal pollution load, combined pollution index.  
26 A REVIEW OF THE APPLICATION OF ELECTROMAGNETIC FIELDS ON MICROBES FOR SURFACE SANITARY WIPES.     , BERNARD, E. E.
The approach in the use of electromagnetic fields (EMFs) has shown antimicrobial effects in different frequencies and intensities. So far, different modalities of EMFs showed antimicrobial and antibacterial effects in different pathogens. However, a novel approach in the use of the EMFs on microbes was carried out using elaborate experimental set up. Apart from the inclusion of ionic pH medium, a short cylindrical pipe was inserted to a short iron core of the same concentric center to form a space in between. Void materials of glass pebbles activated charcoal and saline water (Gel) was filled to the space respectively in accordance with the three experimental set-ups. A coil of wire was inserted around the iron core with the terminals connected to a 12v rechargeable finger battery. These three novel EMFs approaches were conducted under normal prevailing temperature and each of the experimental set up was tested on a table surface infected with pathogens. The novel results showed that the destruction of microbes was 99.9% in faster and better than the prior methods. These results of these experiments will pave way for the optimal industrial application of EMFs to make surface sanitary wipe efficient and effective in Nigeria. Keywords: Electromagnetic Field. Surface Wipes, Microbes, Frequency, Radiation.  
27 Repositioning PTDF as a Source of Cutting-Edge Research in the Oil and Gas Industry: A Collaborative and Innovative Strategies for Knowledge Management.   , Neeka, J,  Mannir, A, Agboola, O and Haruna, M  
The mandate of an organization is fundamental to achieving its objectives in society and the Petroleum Technology Development Fund is not an exception. Research Development and Innovation is one of the Key mandates of the PTDF and repositioning it for the desired purposes in the industry is in high demand and of necessity. In this paper, strategic approaches developed to reposition the research focus of the Fund is examined. Challenges and opportunities are highlighted for possible frontier expansion and restructuring at optimal levels. Oil and Gas industry is highly technical and competitive, requiring the use of the best technologies in solving problems and research development and innovations is the bedrock in achieving and sustaining such goals. The primary purpose of the PTDF as a technology development agency of government must be redirected with state-of-the-act policy to drive research as a cutting-edge tool for national economic development. Secondly, this paper identified key knowledge enablers and inhibitors to the use of research information for industrial development. Accordingly, this paper is useful for research design, policy formulation and structural reform in research development and innovative cycle for the energy industry and other sectors of the economy. Finally, this paper will serve as a source document for the expansion project on research restructuring in Oil and Gas in Nigeria. Keywords: Research Development and Innovation, Strategic Knowledge Enablers and Inhibitors, Frontier Basins, Collaboration and Linkages.  
28 Load Prediction on Metal Forming Process (Forging) Using Finite Element Method.     , Ogbeyemi, A, Okoh, I, Imuero, O and Akpobi, J 
Metal forming process is a widely used manufacturing process especially in high volume metal production system. In this paper, the main objective is using Bubnov-Galerkin finite element model to derive the pressure field set up at various cross-sections of a metal blank during a forging process, and the four Lagrange quadratic elements were assembled to represent the various metal blank. The governing equation adopted for this paper is a one-dimensional differential equation describing the pressures exerted on the forging process. During the analysis, the various metal blanks are divided into a finite number of elements and the weighted integral form for each element were formed after applying the Bubnov-Galerkin weighted residual method. A matrix form under certain boundary conditions from the weighted residual method were used to obtain the pressure distribution across the cross-section of the various metal blanks. Finite element results are obtained for a value of a circular disc diameter, thickness, coefficient of friction, principal stress, length, and radius of a circular material. Finite element method and the Exact solution approach are used to achieve and compare both results. Furthermore, the combination of both methods shows that there are potentials for using this approach towards the optimization of metal forming in manufacturing processes and some engineering practices. Keywords: Forging; LaGrange Interpolation Function; Bubnov-Galerkin Weighted Residual Method; Finite Element Method.