scholarly works
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Item Corrosion protection by novel conversion coatings on structural AI 6061(2022) Oki, M.; Adediran, A. A.; Ikechukwu, A.; Onokohwomo, C. O.; Bosa, C.; Akintola, S. A.; Adesina, O. S.Chromate conversion coatings have witnessed limited acceptability in recent times. The coatings contain Cr (VI) species that have been classified as environmental hazards and injurious to human. Thus, the use of environment-friendly and non-carcinigenic novel inorganic- inorganic hybrid conversion coatings are being explored. Vanadate (VCC), hybrid Vanadate/Molydate (HCC) conversion coatings on A16061 have been classified in terms of corrosion and adhesion performance with reference to the untreated alloy. Natural exposure tests in the atmosphere and stanant near-neutral 3.5% sodium chloride solution, as well as patentio-dynamic polarization measurements showed that the corrosion rate for HCC is lower for Vanadate, which in turn outclassed the ‘bare’ alloy. However, clusters of passive incipient pits were revealed on the former after 120 h of exposure in stagnant chloride solution. Both conversion coatings outperformed the untreated aluminiun alloy after atmospheric corrosion and adhesion tests.Item Fuel energy potential of pyrolyzed municipal solid wastes(2021) Okareh, O. T.; Adegoke, S. O.; Richard, R.; Akintola, S. A.; Adeleke, A. A.; Ikubanni, P. P.Municipal wastes have become a menace and the recycling of these wastes has been the focus of many researches. In this study, municipal plastic wastes were converted to energy fuel using pyrolysis using a locally fabricated vacuum pyrolyzer. 6 kg of municipal plastic wastes (PP, PET and PS) were collected, grounded into chips using a knife milling machine and were fed into the pyrolyzer to undergo thermal degradation at a temperature of 500oC with holding time of 4-5 hours. The pyrolyzed oil was collected into a Pyrex condenser unit and subjected to pseudo-distillation at 100oC to obtain the volatile com-ponents. The percentage pyrolyzed oil mass yield was calculated using mass balance equation. The liquid fuel was analyzed for its physical properties using ASTM methods, while the chemical properties were characterized using FTIR and GC-MS. The pyrolytic process showed the percentage mass yield of the pyrolyzed oil for the municipal plastic wastes oil, char, and non-condensable gas as 82.0, 16.0 and 2.0%, respectively. The derived energy fuel indicated a cloud point, pour point, density and flash point of -26.0oC, -28.0oC, 0.839 g/cc, and 50.0oC and -28.0oC, -35.0oC, 0.744 g/cc, and 30.0 C for pyrolyzed oil and distillates oil, respectively. The FTIR and GC-MS results of the liquid pyrolyzed oil indicate the presence of aliphatic, alkane, alkene, and aromatic hydrocarbons of carbon number C9-C44 in the energy fuel. Physicochemical characterization of the recovered oil indicated similarities with the conventional fossil fuels. The technology has proven to be effective in solving the environmental problems.Item Optimization of drilling cost using artificial intelligence(Medwin Publishers, 2021-11) Akintola, S. A.; Olawoyin, A. B.Drilling operation in the oil and gas industry takes most of the well cost and how fast the drilling bit penetrate and bore formation is termed the rate of penetration (ROP). Since most of the cost incurred during drilling is related to the drilling operations, three is need not only to drill carefully, but also to optimize the drilling process. A lot of parameters are related to the rate of penetration which are actually interdependent on each other. This makes it difficult to predict the influence of every single parameter. Drilling optimization techniques have been used recently to reduce drilling operation cost. There are different approaches to optimizing the cost of drilling oil and gas wells, some of which include static and /or real time optimization of drilling parameters. A potential area for optimization of drilling cost is through bit run in the well but this is particularly difficult due to its significance in both drilling time and bit cost. In this sense, as a particular bit gets used, it gets dull as its footage increases, resulting from the reduction in the bit penetration rate. The reduction in penetration rate increases total drill time. In order to optimize bit cost, it is desirable to find a trade-off between the two by a bit change policy. This study is aimed at minimizing drilling time by use of artificial intelligent for the bit program. Data obtained from a well in the Niger delta region of Nigeria was used in this study and the cost of optimization modelled as a Marcov decision process where the intelligent agent was to learn the optimal timings for bit change by reinforcement policy Iteration learning. This study was able to achieve its objectives as the reinforcement learning optimization process performed very well with time as the computer agent was able to figure out how to improve drilling cost over time. Better results could be obtained with a better hardware and increased training time.Item Application of agro–waste materials for improved performance of water–based drilling fluid(2021-07) Akintola, S. A.; Orisamika, B. O.; Odetola, K. O.Bio–resources and its derivatives have distinctive potential in various industrial applications and solutions especially for captivating usage in drilling fluid formulations for the petroleum industry. Drilling fluids formulations have tremendously advanced through increasing research and development of unique additives to improve their functionalities and meet specific properties in well design operations. In this article, water–based mud formulated with powdered and ash products derived from plantain and banana peels were evaluated. The effects of varying concentrations of these additives and the blends on the performance of the mud were examined by comparison with Low Viscosity Sodium Carboxymethyl Cellulose (LV CMC) for rheology and sodium hydroxide (NaOH) for pH control. The rheology of the mud improves with increasing concentration of the powdered products in a way similar to that of LV CMC. However, powdered banana peels most effectively improved the rheology of the mud to attain 10cp plastic viscosity (PV), 13lb/100sq.ft yield point (YP), 16lb/100sq.ft and 23lb/100sq.ft gel strength at 10seconds and 10minutes, respectively. Plantain peel ashes compared favourably with NaOH in controlling the pH of the mud. Further modification of the products to achieve the same properties as LV CMC is recommended in subsequent studies.Item Modelling the effects of modified local starches on the rheological and filtration properties of a water – based drilling fluid(2021-07) Akintola, S. A.; Isehunwa, S.This study is designed for the comparative analysis of chemically modified local starches used as additive in improving the rheological and fluid loss properties of a water- based drilling fluid. Additives are added to a drilling fluid in order to enhance the various functions of the drilling mud. Different drilling fluid samples were formulated without additive and with various concentrations modified starches. A laboratory investigation on the drilling fluid rheological and filtration properties using the API recommended standard procedures, pressure were studied at 1000 psi with a temperature range of 40.0 to 180.0 ° C, using a High Pressure High Temperature, (HTHP) rheometer and Fann Model 35A respectively From the analyses of the experimental results, it was observed that effective viscosity, plastic viscosity and yield point decrease steadily with increase in temperature. The experimental results, water based drilling fluid treated with chemically modified local starches improves the filtration and rheological properties of the drilling mud. Finally, this paper also presents a predictive model equation good enough to analyse trends and predict future values for effective and plastic viscositieItem Corrosion rates of green novel hybrid conversion coating on aluminium 6061(Elsevier, 2020) Oki, M.; Adediran, A. A.; Ikubanni, P. P.; Adesina, O. S.; Adeleke, A. A.; Akintola, S. A.; Edoziuno, F.; Aleem, A.The use of chromate conversion coatings have been limited by several protocols as a result of their carcinogenicity and toxicity towards humans and the environment. Searches are ongoing for chromate replacement in coating baths and processes. This paper describes the comparison among the corrosion rates of a novel hybrid conversion coating derived from water extracts of hibiscus sabdariffa calyx in conjunction with ammonium molybdate, a molybdate conversion coating and the so-called chromate conversion coating. Potentiodynamic polarization measurement in 3.5 wt% sodium chloride solution was employed in ranking the coatings as sabdariffa molybdate being more corrosion resistant than chromate, which in turn out performed molybdate.Item Evaluation of drilling muds enhanced with modified starch for HPHT well applications(Springer, 2020-10) Sulaimon, A. A.; Akintola, S. A.; Johari, M. A. B. M.; Isehunwa, S. O.The use of carboxymethyl cellulose (CMC) in oil and gas well drilling operations has improved the filtration loss and mud cake properties of drilling muds. The introduction of starch has also reduced, for example, the viscosity, fluid loss, and mud cake properties of the drilling fluids. However, normal starch has some drawbacks such as low shear stress resistance, thermal decomposition, high retrogradation, and syneresis. Hence, starch modification, achieved through acetylation and carboxymethylation, has been introduced to overcome these limitations. In this study, modified starches, from cassava and maize, were used to enhance the properties of water-based muds under high-pressure high temperature (HPHT) conditions, and their performances were compared with that of the CMC. The mud samples added with acetylated cassava or maize starch exhibited the smallest filtrate volumes and filtrate losses within the American Petroleum Institute specification. Therefore, these modified starch-added muds could replace CMC as fluid loss agents since, unlike it, they can withstand HPHT conditions.Item Electron-optical and auger electron spectroscopy studies of a zirconium conversion coating on aluminium(2019) Adediran, A. A.; Oki, M.; Akintola, S. A.Item Electron-optical and auger electron spectroscopy studies of a zirconium conversion coating on aluminium(2019) Adediran, A. A.; Oki, M.; Akintola, S. A.Item Valorized chicken feather as corrosion inhibitor for mild steel in drilling mud(2019) Akintola, S. A.; Oki, M.; Aleem, A. A.; Adediran, A. A.; Akpor, O. B.; Oluba, O. M.; Ogunsemi, B. T.; Ikubanni, P. P.Modified chicken feather reduced the corrosion rate of mild steel in drilling mud as deduced from electrochemical potentiodynamic polarization technique, albeit, with observed infestation of the test environment by microbes over protracted exposure period of 92 days. The corrosion rates with and without the addition of 0.3g of hydrolyzed feather per 100 ml of drilling mud were 1.70 and 1.95 mm/yr, respectively; which corresponded to inhibition efficiency of 13% over the immersion period. The corresponding charge transfer resistances, a measure of corrosion rates were 1480.4 and 1780.0 Ω, respectively; in the uninhibited and hydrolyzed-feather inhibited environments. The voltage over the double layer capacitor as obtained from the polarization studies numerical increased from -0.907 to -0.948 V which indicated adsorption of moieties in the inhibitor and probably some corrosion products on the surface of the mild steel specimen.