scholarly works

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    Improving the rheological and filtration properties of an invert emulsion mud using a locally sourced modified polymer
    (2022) Akintola, S.A.; Sanusi, H.; Oyelola, C.
    Drilling fluid is designed for easy to use, cost effective and environmentally friendly. Several studies have been carried out on the use of local materials such as starch as suitable substitute for imported additives. Due to this short coming resulting from the use of native starch, the potatoes starch was chemically modified using the process of graft copolymerization, before being investigated as an additive for treatment of invert emulsion drilling. Three mud samples labelled (Base fluid, Copolymer 1 and Copolymer 2) were prepared and diesel labelled Base fluid served as control. Varying concentration of additives (1.0 and 2.0 g) were used at added to the different mud samples and laboratory study was carried out using the API Recommended Practice at varying temperature. This study is aimed at improving the properties of an invert emulsion mud using chemically modified locally sourced pomoea batatas as additive
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    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.
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    Investigation of the effect of some salts on the rheological properties of xanthan gum and gum arabic present in a drilling fluid
    (2022) Okaome, P.; Akintola, S.
    The rheological properties of a drilling fluid are important because they allow for extensive examination of the viscosity, fluid flow profile, pressure loss, equivalent circulation density, and hole cleaning capability making it the foundation for all wellbore hydraulics. The viscosity, gel strength, and yield point of Gum Arabic and Xanthan Gum contained in a fresh water-based drilling fluid were investigated in the presence of three distinct salts: calcium chloride (CaCl2), potassium chloride (KCl), and sodium chloride (NaCl). The salts were introduced separately to three distinct fresh water-based drilling fluid samples in increasing weights. The Fann V-G viscometer was used for the required rheology properties measuring the RPM and gel strength. The plastic viscosity, apparent viscosity, and yield point were calculated from the experimental data. With increasing the salt concentration, the plastic viscosity, apparent viscosity, yield point, and gel strength all decreased, which was observed for all three salts used. This research aimed to investigate the effect of three different salts; Calcium chloride (CaCl2), Potassium Chloride (KCl), and Sodium Chloride (NaCl) on the rheological properties of Gum Arabic and Xanthan Gum viscosified water-based drilling fluid.
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    Modeling the effect of modified local polymer on the rheological and filtration properties of water-based drilling fluid
    (2021-10) Akintola, A. S.; Adeniji, A. A.; Mogbolu, U. J.
    In order to achieve a successful drilling operation, the drilling fluid used must be properly designed. Water based drilling muds that are formulated to suit drilling requirements include additives like clays for higher viscosity and starch for better filtration control properties. Locally available yams (Dioscorea) are a good source of starch, with good absorbent properties that give its good filtration control properties but poor gelling properties due to the easily soluble branched chained Amylopectin molecules which causes it to easily degrade. While mud samples treated with Carboxylmethyl cellulose (CMC) was used as control. Chemical modification of starch has been researched to be a good method of improving its gelling properties in water based mud which in turn improves the rheological properties of the mud. Cross linking agents like sodium acetate and ammonium phosphate are used to cross-link the Amylopectin and Amylose molecules in the starch thus making them less degradable. An experimental study was carried out to reduce the yams starch bio-degradable nature via chemical modification with some cross-linking agents (sodium acetate and ammonium phosphate). The results from the rheological and filtration control test carried out on the formulated mud samples treated with modified yams starch additive gave higher gel strength and yield point, exceptional shear thinning ability, lower plastic viscosity and a good but lower fluid loss control when compared to with the control samples. A Factorial design was developed to predict the rheological properties of the mud system at different temperatures and varying starch quantities. The results of the mud samples treated with the non-modified starches, modified yam starches and imported viscosifier (CMC) are indicators that the modified starches improved its gelling nature thereby giving the drilling mud a better rheological properties.
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    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.
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    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.
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    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.
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    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 viscositie
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    Evaluating the effect of drying methods on the properties of a water base drilling mud
    (Science Publishing Group, 2021) Akintola, A. S.; Arigbe, T. E.
    It is important to understand the properties influencing the efficiency of a drilling fluid while drilling for oil and gas. As a result, drilling fluid must be designed in order to comply with three important requirements which are easy to use, cost effective and being environmentally friendly. Several studies have been carried out on the use of local materials as suitable substitute for imported additives. This study focuses on the use of starch processed from local cassava (Manihot esculenta Crant), (TME 419) using the process of wet milling and dried using three different methods namely: oven drying, direct heating and sun drying Due to this short coming resulting from the use of native starch, the starch was chemically modified using the process of esterification before being used as additive for treatment of the water-based drilling. The mud samples were prepared using Wyoming bentonite and distil water as the base fluid. Varying concentration of additives (0.5, 1.0 and 1.5 g) were added to the different mud samples and the laboratory test carried out in accordance with the API Recommended Practice 13B at varying temperatures (30, 50.70 and 90°C). The various mud samples rheological properties was determined using a Fann35A rheometer and the filtration properties using a low –Temperature and High –Pressure API Filter Press at 100 psi with a 3.5” filter paper. The mud samples labelled labeled A, B and C were treated with oven dry, direct heat and sundry modified starches, respectively. While two control mud samples were prepared using low viscous Carboxymethyl cellulose for mud sample D and extra high viscous CMC in sample E. Although the Viscosity and fluid loss profiles result of the mud samples comparable performance with that of the commercial CMC’s. However, mud samples treated with oven dried starches presented the best results in their rheological as well as fluid loss properties.
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    Drilling cost optimization for extended reach deep wells using artificial neural networks
    (Scholars Middle East Publishers, Dubai, United Arab Emirates, 2021) Akintola, S.; Toheeb, T. O.
    Global Petroleum reserves are currently getting depleted. Most of the newly discovered oil and gas fields are found in unconventional reserves. Hence there has arisen a need to drill deeper wells in offshore locations and in unconventional reservoirs. The depth and difficulty of drilling terrains has led to drilling operations incurring higher cost due to drilling time. Rate of Penetration is dependent on the several parameters such as: rotary speed(N), Weight-On-Bit, bit state, formation strength, formation abrasiveness, bit diameter, mud flowrate, bit tooth wear, bit hydraulics e.t.c. Given this complex non-linear relationship between Rate of Penetration and these variables, it is extremely difficult to develop a complete mathematical model to accurately predict ROP from these parameters. In this study, two types of models were developed; a predictive model built with artificial neural networks for determining the rate of penetration from various drilling parameters and an optimization model based on normalized rate of penetration to provide optimized rate of penetration values. The Normalized Rate of Penetration (NROP) more accurately identifies the formation characteristics by showing what the rate should be if the parameters are held constant. Lithology changes and pressure transition zones are more easily identified using NROP. Efficient use of Normalized Penetration Rate (NROP) reduces drilling expenses by: Reducing the number of logging trips, minimizing trouble time through detection of pressure transition zones, encouraging near balanced drilling to achieve faster penetration rate.