scholarly works

Permanent URI for this collectionhttps://repository.ui.edu.ng/handle/123456789/564

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Start date: 2000End date: 2019

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Now showing 1 - 10 of 86
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    Development of thermodynamic model with gopal’s constants for the Inhibition of gas hydrates formation in gas pipeline
    (2019) Akinsete, O. O.; Akintola, A. S.; Folayan, O. G.
    Hydrate deposition remains a very willful one in the oil and gas industry and costs the industry billions of dollars worldwide for prevention and remediation in pipelines and flowlines. An economic and environmentally friendly solution to the prevention of hydrate formation is prohibitively expensive. In this study, a thermodynamic model for hydrate inhibition in gas pipelines by applying the Joule Thomson Expansion phenomenon was developed. The model is a function of the specific gravity, initial and final temperatures, and the initial and final pressures. This developed model comes with the Gopal's constants that make the model trainable to fit data from various expansion processes. The results obtained for sweet gases were compared with that presented by the Gas Processors Suppliers Association (GPSA) and an error of less than 5% (R2 = 0.9629) was observed. The effect on sour gases was also considered. The pseudo-reduced temperature ranges from 1.05
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    Economics of local materials as base fluids in the formulation of an oil based mud
    (2019) Akintola, S.A.; Atere, E. B.
    The use of drilling fluid is an important aspect in drilling operations as its critical to ensure a safe and productive oil or/ and gas well. In the bid to protect the environment and reduce environmental pollution resulting from drilling activities while using the No. 2 diesel, it is necessary to search for an alternative that will be suitable, locally available, easily affordable vegetable oils which is environmentally friendly and non-toxic as base fluid. This study is aimed at investigating the properties and economics analysis of the use of non-toxic, biodegradable locally obtainable oil from the palm kernel seed (Oil X) and coconut (Oil Y) as base fluid in the formulation of an Oil Based Mud. The rheological and filtration properties of the mud samples were evaluated using the API Recommended Standard, while the economics analysis was performed using the Net Present Value (NPV) and discounted profit to investment ratio (DPI) models. The results of the rheological, filtration and physiochemical properties for both X-OBM and Y-OBM, showed the possibility of the use of oil X or Y as base fluid as against No. 2 diesel. The result from the NPV model showed that the use of oil X or Y provided a higher NPV compared to those of No. 2 diesel mud even though the cost of No. 2 diesel was lower than those of X and Y oils. Also the discounted profit to investment ratio (DPI) was also better for mud formulated from the vegetable oil muds Although the initial cost of formulating mud samples using oil X or Y compared to No. 2 diesel Oil Base Muds (OBM) seems higher, consideration of their fire capacity resistance, nonimpact on the environmental and the cost of disposal of OBM the application of vegetable oil X or Y is more viable than No. 2 diesel in the industry
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    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.
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    Flow assurance in kumuje wet-gas pipeline: analysis of pigging solution to liquid accumulation
    (2018-09) Akintola, S.; Folorunsho, E.; Ogunsakin, O.
    Liquid condensation in gas-condensate pipelines in a pronounced phenomenon in long transporting lines because of the composition of the gas which is highly sensitive to variations in temperature and pressure along the length of the pipeline. Hence, there is a resultant liquid accumulation in onshore wet-gas pipelines because of the pipeline profile. This accumulation which is a flow assurance problem can result to pressure loss, slugging and accelerated pipeline corrosion if not properly handled. Kumuje wet-gas pipeline is an onshore 19" carbon steel line which is approximately 70 km long in a hilly terrain with an elevation of 700 m above sea level. With the pipeline’s maximum design gas capacity and field operational capacity pegged at 165 and 135 MMSCFD respectively, this study was tasked with proposing an efficient pigging scheme for the removal of liquid inventory from the pipeline using the capacity of the slugcatcher as the basis for the scheme, also, factors which affected liquid accumulation and pigging efficiency was investigated using a dynamic multiphase simulator – OLGA. Using OLGA 2016.2, both steady and dynamic runs were carried out in other to investigate into some critical factors such as pipe profile and inclination, pig velocity, gas velocity, bypass pig leakage etc. that influence liquid condensation and holdup in a wet-gas pipeline. Of the three (3) pigging schemes considered, scheme 2 proved to be the ideal operational scheme because the surge volume (395 m3) generated by the pig is within the handling capacity of the slugcatcher (600 m3). Also, liquid holdup was seen to be strongly influenced by the pipe profile and a high flow-rate was observed to significantly reduce the volume of liquid held-up in the pipeline. Conclusively, OLGA simulator proved to be an excellent tool in simulating dynamic multiphase flow and predicting liquid holdup in wet-gas pipelines in a hilly terrain.
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    Conversion coating pretreatment enhances pipeline integrity
    (2018) Oki, M.; Adediran, A. A.; Ogunsemi, B.; Akintola, S. A.; Charles, E.
    It is necessary to coat both the internal and external surfaces of pipelines which transport different types of fluids that are usually contaminated with various percentages of aggressive corrosives. Pipelines pass through various terrains and highly challenging environments hence the need for both internal and external coatings to prevent corrosion and its adverse effects. In order to improve on the longevity of pipelines and the adhesion of the coating system, it is preferable to conversion coat blasted surfaces prior to application of any coating system. Improvements in pipeline coatings applications and the often neglected chromating procedure prior to coating application have been highlighted. This will prolong the lifespan of pipeline networks and secure these strategic assets from being a source of both materials and human resources drain pipes. However, the use of corrosion resistant alloys as internal lining for carbon steel pipes in the petroleum/gas industry is fast gaining recognition.
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    The prospect of using modified local starches from cocoyam and wheat starches as fluid loss material in a water - based drilling
    (2017-06) Akintola, S. A.; Ogundipe, M.
    As an oil producing nation, Nigeria embarks on substantial drilling activities. The additives used for these activities are all imported as a result there is need to reduce the over dependency on foreign additives this has necessitated the sourcing locally for suitable substitute. During drilling, adequate filtration control is essential to prevent drilling problems such as excessive torque and drag; differential pressure sticking; borehole instability; and formation damage. This study was aimed at a comparative analysis of the use of wheat starch and cocoyam chemically modified with ammonium phosphate and sodium acetate as suitable fluid loss additives in a water-based mud. The filtration properties of a water- base fluid formulated with variable quantities of the chemically modified starch were determined using the recommended standard API practice at different conditions of temperatures with Carboxymethylated Cellulose CMC used as control. Using Eviews 7, the statistical analysis showed drilling fluid formulated with starches treated with sodium acetate had a fluid loss value in the range of 4.0 - 8.9 mls, while those from starches modified with ammonium phosphate had a fluid loss of 4.3 - 8.3 mls; although, these values were lower than 9.1 - 11.1 mls for CMC formulated mud, the results show that mud sample treated with modified wheat starch and cocoyam starch can significantly reduce fluid loss in a water based drilling mud, thereby confirmed that polymer can be used as fluid loss control agent in the mud system
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    Prediction of generalised and localised carbon steel corrosion using improved Norsok and Papavinasam models
    (2017) Falode, O. A.; Akintola, S. A.; Akintomiwa, I.
    In this study, Norsok and Papavinasam models have been improved so as to reduce the model limitations. The Norsok model was improved by accounting for 3 phase flow in calculating the wall shear stress and correcting for oil wetting and formation of protective layers in steel pipes during hydrocarbon transportation while the Papavinasam model was improved by using the Weibull distribution to account for time effect in corrosion predictions. The corrosion rates predicted fairly agreed with the field values. The improved models are user friendly and readily available and thus applicable for corrosion studies in the oil and gas industry.
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    The prospect of using palm wine as a fluid loss control agent in water based drilling mud
    (Avanti Publishers, 2016) Akintola, A. S.; Isehunwa, S. O.; Oboh, S. M.
    The need to advance and project the use of local materials as suitable drilling fluid additive in the oil and gas industry in Nigeria led to the research on the possible use of palm wine and potash as additives in a water base drilling mud. A comparative study of these local materials (palm wine and potash) with imported foreign materials (lignite and caustic soda) as control were used in investigating the properties of a water base drilling fluid. A laboratory investigation of the effects of temperature and aging time on the properties of water-base drilling fluid is made with Fann Model 800 High Temperature and a High Pressure (HTHP) Viscometer, according to the API recommended standard practice. The results obtained showed similarity in the drilling fluid’s rheological and filtration properties; mud weight and pH values for both local and foreign additives. The result from the mud sample prepared from the palm wine and potash had apparent viscosity, plastic viscosity and yield point decreasing steadily with increase in temperature for all aging time just as shown with the control sample, while the aging effect diminishing as the aging time increases. The potash was seen to have increased the mud pH from 7.0 to 12.9 pH units. The results, shows that both palm wine and potash can be used as suitable in water base drilling mud additive.