Browsing by Author "Akintola, S. A."

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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.
Classical modelling of the effect of heterogeneity on reservoir performance of agbada formation
(Nova Science Publishers, Inc., 2015) Akintola, S. A.; Akinsete, O. O.; Akan, O. G.
Understanding the basic mechanisms that govern flow of hydrocarbon in any given reservoir situation is necessary in developing reliable methods of predicting behaviour in that reservoir. Most reservoirs in Agbada Formation of the Niger Delta Basin are anisotropic and therefore heterogeneous, which is a vital parameter in the efficient production of hydrocarbons. This work looked at the effect of permeability anisotropy (Kv/Kh) or heterogeneous distribution and its effects on reservoir performance using windows based IPM-MBAL petroleum engineering software. Results analysis revealed that anisotropy makes reservoir production modelling more realistic than the isotropic scenarios, and degree of heterogeneity improves oil recovery from the reservoir (Kv/Kh = 1, R.F = 49.31%; Kv/Kh = 0.1, R.F = 49.95%; Kv/Kh = 0.001, R.F = 50.60%; Kv/Kh = 0.0001, R.F = 51.24%). Reservoir heterogeneity should be included in reservoir modelling practices because it has a significant effect on hydrocarbon production.
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.
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.
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.
Development of modified fractional flow equation for non-darcy flow in computer simulation of oil reservoirs
(2021-06) Akintola, S. A.; Adeaga, O. A.; Muritala, O. K.
Upon the depletion of oil reservoir, huge amount of oil is usually left behind. This oil, in some cases double the initial oil recovered, in order to recover the unrecovered oil, different types of secondary oil recovery techniques can be explored. A more common techniques is water flooding which involve the injection of water into reservoir to displace oil into the wellbore. To determine the relative flow rates of oil and water at any point in a porous flow system while also examining factors such as fluid properties, rock properties, reservoir structural properties, pressure gradient, and flow rate which affect the displacement efficiency of a water flooding project, the fractional flow equation is employed. But the convectional fractional flow equation is applicable just to Darcy flow. The use of Darcy flow equation is not applicable in low permeability sandstone reservoir, hence non Darcy flow have been used one of such equation is the Forcheimer equation, as a result this study is aimed at modifying the Forcheimer equation and validating the new fractional flow equation using literature. The result obtained showed that the proposed equation predicts better than Forcheimer equation.
Electron-optical and auger electron spectroscopy studies of a zirconium conversion coating on aluminium
(2019) Adediran, A. A.; Oki, M.; Akintola, S. A.
Electron-optical and auger electron spectroscopy studies of a zirconium conversion coating on aluminium
(2019) Adediran, A. A.; Oki, M.; Akintola, S. A.
Estimation of the refractive indices of some binary mixtures
(AcademicJournals, 2015-04) Isehunwa, S. O.; Olanisebe, E. B.; Ajiboye, O. O.; Akintola, S. A.
Refractive index is a useful fluid characterization parameter with widespread industrial applications. The value for many pure liquids are known or readily available in literature. However, when experimental literature are not available, the refractive indices of binary and multicomponent liquid are often estimated from the pure components using mixing rules which are sometimes not accurate. This study was designed to measure the refractive indices and evaluate the accuracy of some commonly used mixing rules when applied to benzene-toluene, heptane-hexane, hexane-acetone, heptane-acetic acid and acetic acid-acetone binary mixtures at varying volume fractions and temperatures between 20 and 60˚C. A simpler relation based on modified Kay or Arago-Biot mixing rule was demonstrated to have wider range of applicability because of the explicit temperature-dependence term.
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.
Field study of drilling bits performance optimization using a computer model
(2015) Oriji, A. B.; Zakka, B.; Akintola, S. A.
One of the major problems facing drilling operations is the performance of the drilling Bits. The ability of the Bit to crush the rock and the removal of the crushed rock from the wellbore effectively. It is necessary to understand the fundamental difference in Bit design for different rock textures because many variables tend to affect Bit optimization, particularly the type of formations, economics and Bit selection. However, the cost of drilling a well has a considerable effect on the selection and the design of a particular Bit, therefore this paper focuses on the development of a model that will predict future Bit performance and optimization for actual well design and construction. The variables to optimize Bit performance provide means of handling cost estimation hence the model becomes more realistic and dynamic in its application. The input variables and control factors for this model are stretched to minimize cost and maximize performance. The cost per foot and the break even calculations were done using data from the reference well X14 and also the evaluation well X35 from a field-X in the Niger Delta region. A Visual Basic dot Net program model was developed, tested and validated with the real field data to know its accuracy. The model interface shows the detailed application of the Bits in validating the data to provide the equivalent results for the five different Bits. Each set of the Bit record was ran separately on the software and the results for each application developed for comparison. In the software, data application were grouped into two distinct methods namely; rentals method and historical method. Under the rentals method, data were uploaded into the software and ran to generate results while the historical method was basically used for model prediction. The breakeven analysis provided a technique for calculating the performance required for an alternative Bit type to match the cost per foot of the current Bit. Based on the model results, Hughes Tungsten Carbide (HTC) Bit and Security Bit (SEC) used to drill well X14 and X35 were well optimized and should be encouraged in drilling wells within the area.
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.
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
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.
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.
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
Reinforcement bar corrosion - causes and management
(IOP Publishing Ltd, 2019) Oki, M.; Akintola, S. A.; Adediran, A. A.; Peter, P.; Ikubanni, P. P.; Ogunsemi, B. T.
Concretes are composite materials which decay as a result of steel corrosion in concrete structures is mostly accelerated in environments laden with chlorides and industrial effluent gases as well as harsh chemicals employed in and those generated from wastes in agricultural industries. This review summarises the effects of various environmental pollutants which promote deterioration of concretes with resultant corrosion of reinforcing bar (rebar). An overview of traditional and current methods for significant reduction of this mode of material deterioration is described. Discussions on management tools for rebar corrosion in agricultural and marine environments have been highlighted. Repair methods include the traditional application of patch repair mortar which has been modified with polymeric materials to improve adhesion and reduce porosity. The use of cathodic protection system to reduce rebar corrosion to its barest minimum has gained currency. Attention should be directed at corrosion reduction practices at the design and planning stages as well as modification concrete mixes with modified agricultural wastes/products and polymers.
The use of crassostrea virginica as lost circulation material in water-based drilling mud
(2014-12) Akeju, O. A.; Akintola, S. A.; Akpabio, J. U.
Lost circulation of drilling fluid results in higher operational expenses which makes it imperative to design the fluid, such that minimal invasion of the fluid occurs in the formation. To achieve this, Lost Circulation Materials (LCM) are required which is expected to seal the fractures hence, the performance of Oyster Sea-shells (Crassostrea Virginica) as a lost circulation material is being investigated knowing that it is rich in Calcium Carbonate. Sea shells were prepared, pulverized and sieved to obtain fine grain particles which were analyzed in the laboratory for various properties. A fractured zone lost circulation test procedure was employed using a medium-sized fracture at 1000 psi. pressure drop and temperature of 808ºF. The tests were performed in triplicates and the rheological and gel strength results were obtained. It was seen that although the Oyster Sea shell is not a viscosifier, it passes API acceptability test for API acceptable range of Plastic Viscosity and Yield Point. The plastic viscosity and Yield point of the mud were compared to that of the VG Gel and the trend observed was a good indication that the Oyster Sea shell would support Wyoming bentonite. Locally sourced Oyster Sea-shell can be used as a lost circulation material as its fine-sized grades performed excellently in controlling mud loss for the water-based mud in the laboratory. The 2:1 blend of Oyster Sea-shell outperformed the 2:1 blend of coarse and medium ground walnut shells in some of the water-based drilling mud tested; hence, the Oyster sea shell is a suitable substitute for conventional LCMs.
Use of cassava skin and coconut husk as lost circulation material in water-based mud
(2016) Akintola, S. A.; Aina, A. O.
During oil and gas drilling operations, lost circulation of die drilling fluid could result in higher operational expenses this makes it imperative to design the drilling fluid to be ised so as to minimize the invasion of the drilling fluid into the formation. Several materials had been proposed for use as Lost Circulation Material (LCM) but the use of the cassava skin and coconut husk have not been investigated. Water based mud prepared from bentonite and water, was used for the mud formulation Cassava Skins (CSS), Coconut Husks (CCH). were sun dried, shredded and blended to obtain fine to coarse fibrous and flaky particles respectively, Ground Marble (GM) was used as the control. These were used in the different concentrations ranging from 5ppb to 25ppb for the various drilling mud sample, and analyzed in the laboratory for particle sizing (which depends on the type of loss zone) using particle size distribution of material with the densities of the various samples ranging between 8.6 to 8.9 ppg. The viscosity for the mud sample with no LCM (16 cp) was a little higher while a gradual (but not linear) increase was observed for the 5 ppb to 25 ppb concentrations . A lost circulation test procedure for high permeability and fractured loss zones was performed using a 300 microns pore size, 508 and 1016 micron fracture width at 1000 psi pressure differential and temperature of 120 c F. This study is aimed at examining the impact of these local Lost Circulation Materials (LCMs) - Coconut Husk and Cassava skin on the rheological and thixotropic properties of a water based mud and its effectiveness as a loss circulation material under static condition. Although the LCMs had no significant effect on mud rheology, it passed the API acceptability test range for plastic viscosity and yield point.
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.