School of Egineering and Engineering Technology

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Open Access
Implementation of experimental design in evaluating the mechanical properties of ceramic composites
(Worldwide Open Access Publisher, 2022) Asotah, Wisdom; Onuoha, Chukwudike; Medupin, Olawale; Elakhame, Zeberu
The influence of independent variables (firing temperature and residue content) on mechanical properties – hardness, compressive strength, flexural strength, compression modulus and energy at the break – of ceramic composites was investigated through experimental design. Microstructural evaluation using scanning electron microscopy (SEM) and mineralogical identification using x-ray diffraction (XRD) was also accomplished to understand the structure-property relationship. In analysing the observed data, variance analysis was employed to determine the statistical significance of the factors on the responses and regression equations showing correlations were developed. The observed data were shown to accept the null hypothesis for hardness, compression modulus and compressive strength, while flexural strength and energy at break rejected the null hypothesis judging by the p-value. The flexural strength showed a good correlation, but the influence of firing temperature and residue was minimal. However, both factors' square was shown to influence the flexural strength considerably. The study presents a systematic way to understand causal relationships, ensuring that product specifications and quality are met.
Open Access
Modeling the mechanical properties of clay powder filled recycled low density polyethylene composites
(Scientific Research Publishing, 2020-07-31) Onyedika, Gerald Okwuchi; Onuegbu, Genevive Chinyere; Onuoha, Chukwudike
This study modeled some mechanical properties of clay powder filled recycled low-density polyethylene, rLDPE (rLDPE composite). The rLDPE is commonly referred to as used sachet water bags. The clay powder (filler) was obtained by sun-drying, grinding, and sieving. Two particle sizes of clay powder were used: −90 µm and −425 µm to represent the passing sizes at different clay powder contents of 5, 10, 15 and 20 wt% which were thoroughly mixed with the recycled low-density polyethylene in an injection molding machine at 173˚C. The results showed that the tensile strength, tensile modulus, hardness, flexural strength, fatigue strength and hardness increased with increase in clay powder contents. However, there were decreases in strain-at-breakage and shear strength as clay powder content increased. Model equations showed that smaller particle size enhanced the mechanical properties and equations generated can be used to predict the properties of composites at predetermined clay contents. Standard deviations obtained for the various mechanical properties show that the model, in most cases had the lowest degree of scatter (dispersion) than those of −90 µm and −425 µm. Hence, these models are suitable to predict outcomes of the properties of the clay filled recycled low-density polyethylene composites
Open Access
Tribological behaviour of periwinkle shell powder-filled recycled polypropylene composites
(SciPress, 2019) Onuoha, Chukwudike
Polymer composites are increasingly replacing metals in structures such as gears, wheels, clutches, housings, bushings and other areas where tribology is of great importance. Various ways are used to improve the tribological behaviour of neat polymers, and the most familiar method is the incorporation of fibres/fillers in the polymer to produce composites. In this present research, the tribological behaviour of periwinkle shell powder-filled recycled polypropylene composite was studied. Injection moulding was used for the preparation of the composites and the impact strength, wear resistance and fatigue strength were examined. SEM was utilized to support the discussion of the results. The results showed that the incorporation of periwinkle shell powder into polypropylene improved the wear resistance and fatigue strength but showed no improvement in impact strength
Open Access
Characterization of Ibere clay for the production of electrical porcelain pin insulators
(International Research Journal Publishers, 2014-06) Onuoha, C.; Ovri, J. E. O.; Mark, U.
The characterization of Ibere clay for the production of porcelain pin insulators was carried out for both the locally made porcelains and the standard. Test samples were made by varying the compositions of feldspar and quartz needed to form a mouldable plastic body with the clay. The following properties were determined: electrical resistivity, apparent porosity, water absorption, bulk density and linear shrinkage. Results obtained showed that apparent porosity, water absorption and electrical resistivity increased with increase in the composition of the non-plastic materials (feldspar and quartz) while bulk density and linear shrinkage decreased with increase in non-plastic materials. The chemical composition of the clay (43.94%SiO2, 26.54%Al2O3) compares well with previous works (40-60%Si2O, 25-45%l2O3) for the production of ceramic refractories. Linear shrinkage (8.33-9.68%), apparent porosity (10.81-17.30%) and water absorption (5.4110.84%) are in conformity with standards (7-10%, 16.45% and 8.20% respectively). Electrical resistivities recorded (0.79-1.39 x 107Ω-m) are in agreement with results obtained for standard (0.45 x 107Ω-m). These results are obtained in samples containing 50-70% clay, 20-30% feldspar and 10-20% quartz. It is therefore concluded that imported porcelains used by Power Holding Company of Nigeria (PHCN) can be replaced with porcelains made from Ibere clay.
Open Access
Optimization of biodegradation of anthracene by corynebacterium sp and pseudomonas putida
(U.P., 2015-05) Azeez, Taofik Oladimeji; Owabor, Chiedu Ngozi; Nwakaudu, Madueke Stanley; Usondu, Nnamuzie Francis
The carcinogenic potential of industrial effluent discharged of anthracene on the ambient environment withcontamination to soils and aquifers is not only environmental concern but difficulty in implementation of biodegradation of anthracene due to inability to optimizing the process parameters. The optimization of process parameters for biodegradation of anthracene with the activity of Corynebacterium sp and Pseudomonas putida using response surface methodology was aimed to be investigated. A 23 of full factorial central composite design was employed for developed quadratic polynomial model to achieve optimal performance of the process. Statistically,high correlation coefficient (R2 ) for quadratic polynomial model for biodegradation of anthracene by activity of Corynebacterium sp 0.9659 (p<0.05)and Pseudomonas putida 0.9939 (p<0.05)were obtained. The optimum conditions for anthracene degradation by Corynebacterium sp were 69.99g/L, 83.20hours and 3.4735vvm with about 98.48 percent of anthracene degraded while Pseudomonas putida were 69.989g/L, 83.58hours and 3.5vvm with 89.51percent of anthracene degraded.
Open Access
Predictive modeling of Nigerian peak condensate using Hubbert’s zero annual reserve rate
(Vandana Publications, 2015) Kamalu, C. I. O.; Appah, D.; Obah, B.; Anyanwu, E. E.; Obijiaku, J. C.; Uzondu, F. N.; Okolie, I. J.; Oghome, P.
In this work, a model was developed using Kamalu’s (2010) natural resource depletion word equation in one hand and Hubbert zero rate of annual reserve concept on the other hand. Experimental data was collected from Nigerian Ministry of Petroleum and Minerals, 7 Kofo Abayomi Street, Victoria Island, Lagos to validate the model. It gave coefficient of correlation of 0.99997 and 0.99517 for discovery and production of Nigerian condensate respectively. It was also established that Nigerian condensate will exhaust in the year 2518 AD when the discovery and production values will be equal to 110MMB. The research reveals that there is a gentle interaction between the cumulative discovery and production and serious interaction between annual discovery and production as years roll by. This work can be used by Nigerian government to plan their condensate budget both nationally and internationally and to cushion their position in OPEC and the world
Open Access
Effects of extraction techniques on the yield and mechanical properties of empty plantain fruit bunch fibers
(Vandana Publications, 2015-12) Obijiaku, J. C.; Kamalu, C. I. O.; Osoka, E. C.; ,Onyelucheya, O. E.; Uzondu, F. N.; Obibuenyi, J. I.
Two major techniques; water retting and dew retting, were used to extract natural fiber from empty plantain fruit bunch. Four different size categories each comprising of a group of six (6) bunches were used for the water retting experiments and two size categories each of six (6) bunch samples were used for the dew retting experiments. Results for the water retting experiment showed that the fiber yield is enhanced by the addition of a load/weights on the retting bunch and the bunch size, while results for the dew retting revealed that fiber yield is dependent on both retting time and bunch size. Results of statistical analysis produced optimum yield value of 85.95% with a maximum dded weight of 5kg and bunch diameter size of 4cm for the water retting, and for dew retting, an optimum yield value of 60.38% for the bigger bunch size of 5.5cm when extracted on the same day of harvest. Mechanical tests on fiber from the two techniques showed better mechanical properties for the water retting categories with a maximum tensile strength of 823.295N/mm2 and modulus of elasticity (MOE) of 644.318N/mm2. The fiber extracted finds use in the manufacture of reinforced composite materials which are fast replacing the use of metallic and plastic materials, due to the quest for materials that are light and cheap, yet strong.
Open Access
Mathematical modelling of drying characteristics of pepper (Capsicum annum)
(U. P., 2015-09-15) Nkwocha, A. C.; Kamalu, C. I. O.; Dadet, W. P.; Uzondu, F. N.; Ogbonna, O. C.
The effects of drying condition on the drying behaviour of pepper (C. annum) and the applicability of three thin-layer drying models namely; Page, logarithmic and Flick’s law, to predict the drying behaviour of pepper were studied. The experiments were conducted in a constant temperature hot air drying oven. Three temperatures (50, 60, and 700 C) were studied. Drying air temperature was found to be the main factor affecting the drying kinetics of pepper; raising the drying temperature from 500C to 700 dramatically reduced the drying times. Higher equilibrium moisture contents were obtained at lower temperatures. Furthermore, drying was observed only in the falling rate period, and comparison among drying models was made using statistical analysis to select the best fitting model for the drying curves. Among the three tested models, Page model was found to be superior to the other models in terms of fitting performance, in fitting the experimental data, providing the highest coefficient of determination (R2) value -0.9944, and the lowest root mean square error (RMSE) value - 0.03032.
Open Access
Mercerized Milletia sp fiber epoxy composites: Fiber loading, aspect ratio and mechanical properties
(U. P., 2018) Uzondu, Francis Nnamuzie; Onukwuli, Dominic Okechukwu; Azeez, Taofik Oladimeji; Osoka, C. Emmanuel; Obibuenyi, John Ifeanyi
The fiber loading capacity and poor adhesion between fibers and matrix remains an area of concern in fiber polymer composites. The fiber loading capacity and aspect ratio of mercerized milletia sp fiber on mechanical properties (tensile strength, tensile modulus, tensile toughness, elongation, flexural and impact strength) of Milletia sp fiber epoxy composites was investigated. Milletia sp fiber was extracted using water retting approach. The extracted fiber was mercerized at optimum treatment conditions of 5.84 wt% NaOH and 42.58mins. The epoxy composite samples were prepared using hand layup method for epoxy 103 and amine hardner in a ratio 2: 1 and commingled with untreated and treated fiber, respectively, at optimum treatment conditions. The fiber loading of 10 – 50 wt% and aspect ratio of 42.68 – 213.38 mm/mm were used. The mechanical properties of mercerized milletia sp fiber epoxy composite were determined and optimized using RSM of MATLAB statistical tool box. The tensile strength, tensile modulus, toughness, elongation, flexural strength and impact strength for epoxy resin was 44.2 MPa, 1.9716 GPa, 0.8177 MPa, 3.1%, 85.4 MPa and 360 Kj/m2, respectively. At optimum aspect ratio and fiber loading, the mercerized milletia sp fiber increased the tensile strength, tensile modulus, toughness, elongation, flexural strength and impact strength of the epoxy resin by 46.38, 77.75, 97.99, 18.81, 125.06 and 217.78%, respectively. Thus, mercerized Milletia sp fiber enhanced the mechanical properties of epoxy composites.
Open Access
Environmental assessment of vehicular emission in Port-Harcourt City, Nigeria
(U. P., 2017) Nkwocha, A. C.; Ekeke, I. C.; Kamalu, C. I. O.; Kamen, F. L.; Uzondu, F. N.; Dadet, W. P.; Olele, P. C
Port Harcourt is a coastal city located in the Niger Delta region of Nigeria, with very short dry season and long heavy rainy season periods. The objective of this study was to assess air pollution level from vehicular emission during the rainy season period. Three locations in the city noted for high traffic congestion were selected for the study. Air sampling in these locations were carried out for 11 days, covering peak and off peak periods. The following air pollutants were measured namely; nitrogen oxides (NOx), sulphur oxides (SOx), carbon monoxide (CO) and unburnt hydrocarbons (CxHy), as well as climatic elements – ambient temperature and relative humidity. The air pollutant levels obtained were compared with local and international standards. CO complied with interthe health risk associated with ainational standard, but exceeded local standard. There is need for effective air pollution monitoring and control, this will go a long way to reduce the health risk associated with air pollution in the city..
Open Access
Vaporization models of varying crude oil characteristics
(Asian Network for Scientific Information, 2011) Uzoije, A. P.; Uzondu, F. N.; Agu, P. C.
The purpose of this study is to provide models for quick assessment of vaporized hydrocarbon from an oil spilled soil. Vaporization is a dominant mechanism which manifests at the initial period of crude oil spill. Quantification of these vaporized hydrocarbons without going through the rigorous methods of weighing and other experimental methods is always beneficial to science and technology. Modeling of the crude oil vaporization rates enhances quick quantification of vaporized hydrocarbon concentrations. In this study, the experimental data obtained from the vaporization process of crude oil of different consistency (different hydrocarbon concentrations) spiked on different soil samples (soils of different textural characteristics) were fitted into the following kinetic models; zero, first and second order. It was observed that zero order kinetics best fitted the vaporization of sample A crude oil (crude oil of the highest hydrocarbon concentration) from different soil samples with vaporization from soil D (soil with the highest percentages of clay and organic matter) showing the highest linear coefficient (R2) of 0.95. The kinetic study equally showed that first order kinetic model was sufficient to quantify the vaporization rate of crude oil sample C (crude oil sample with lowest hydrocarbon concentration) given the fact that the rate equation models for its vaporization from all the soil samples showed linear coefficients (R2) of between 0.611-0.87. Vaporization rate of oil sample B obeyed the second order kinetic model. Generally, the results showed the dependability of the kinetic models to varying crude oil and soil types. The models help us get good insight into providing solution to our environmental problems as it pertains to crude oil spill on land.
Open Access
Biopolymer substitution and impact on cuttings transport of a lightweight water-based drilling fluid
(STM Journals, 2017) Uwaezuoke, N.; Onwukwe, S. I.; Igwilo, K. C.; Obah, B.
The challenges associated with natural gas Pipeline flow assurance is an increasingly important issue as the world supply for natural gas expands, and is expected to rise more strongly to match the global demand for a cleaner energy. Flow assurance challenges in pipelines include hydrate formation, paraffin wax deposition, asphaltene deposition, sand deposits, black powder, and on the wall of pipelines, all of which obstruct the flow of well fluids and associated produced hydrocarbons. This study addressed these flow assurance concerns from a technical view by quantifying the threats and establishing appropriate mitigation schemes, leading to designed solutions and operational procedures. Modeling and simulation approach was adopted to achieve the overall aim. The simulation software tools PVTsim and OLGA were used for both steady state and dynamic states. The phase envelope investigation indicates that the cricondentherm within the constraint of the delivery temperature. The slugging analysis, indicates that hydrodynamic slugging will not be predominant for the pipeline operations at the design flow rate of 30MMscfd along Alakiri – Obigbo, and at 70MMscfd along the Obigbo Tie-in - Intermediate scrap station; as the flow regimes are mainly stratified for both pipeline systems. From the hydrate analysis investigated, after a shutdown period (no-touch time); hydrate threat is envisaged during the shutdown period of the Intermediate scraper trap – ALSCON along pipeline system, since the temperature drops to the hydrate formation temperature.
Open Access
Performance characteristics of Parkia biglobosa as fluid loss control agent in aqueous mud system
(2020) Uwaezuoke, Nnaemeka; Onwukwe, Ibuchukwu S.; Igwilo, Chinweuba K.; Duru, Ugochukwu I.; Obah, B
Recent trend in the use of biomaterials in oilfield applications involves minimum refining and purification. The effectiveness of Parkia biglobosa as fluid loss control additive in aqueous based mud was tested according to API standard. The effect of temperature on the formulation was determined to identify any deviation due to presence of the material in the formulation. At 8ppb concentration used, 3.6mL fluid loss and 1.1mm filter cake thickness were recorded; compared with 8mL and 0.8mm, and 5.4mL and 0.8mm of Pleurotus and PAC respectively. Both fluid loss and filter cake thickness increased with increase in temperature. A low-flat discontinuous gel was observed at elevated temperatures which is desirable. Other drilling fluid rheological parameters were not adversely altered by the presence of the material, even at elevated temperature conditions. The biodegradable material was found to be suitable as fluid loss agent, both in effectiveness and environmental consideration since it is biodegradable, and might reduce cost of formulation since minimum processing is required.
Open Access
Data on shale-water based drilling fluid interaction for drilling operation
(Elsevier, 2018) Okoro, Emeka Emmanuel; Igwilo, Kevin C.; Mamudu, Angela Onose; Ekeinde, Evelyn Bose; Adewale, Dosunmu
The shale dispersion test (rolling test) is a common procedure that is used to measure the interactions between drilling fluids and shales. The shale rolling test depends on the moisture content of the shale, the shale composition, the viscosity of the test fluid, the rotation speed of the rollers, and the test temperature. The rheological behavior of the test fluid has the strongest influence on test results. The data was generated experimentally, shale samples from Agbada an formation Niger-Delta was used. These shale samples were cored at a depth of 2000ft and 3400ft. Water based mud that will minimize shale dispersion and swelling of shale was formulated. The dispersion test was conducted, and it involves exposing a weighted quantity of sized shale to the formulated mud in roller-oven. This test is used to design fluids and screen the effectiveness of inhibitor additives to maintain the integrity of the cuttings and minimize the interaction of fluids with the shale sections during the drilling and completion operations. The swelling test was conducted and the linear expansion adopted because it is the most representative of the increase seen by the wellbore but was measured in the direction perpendicular to the bedding plane as this is the direction of swelling into the wellbore.
Open Access
Cellulosic Cyperus esculentus L. as a filtrate loss modifier in field applicable aqueous and non-aqueous drilling fluids
(Springer, 2019) Okoro, Emeka Emmanuel; Igwilo, Kevin C.; Ifeka, Kelvin; Okafor, Ikechukwu S.; Idowu, Sangotade
The design and formulation of drilling fluids require additives that are cost-effective and environmental friendly in line with international best practices. This study was conducted to investigate the potentials and effects of Cyperus esculentus (Tiger Nut) as a filtrate loss modifier in field applicable aqueous and non-aqueous drilling fluids. Sixteen (eight aqueous and eight non-aqueous) drilling fluid systems were formulated, four aqueous and non-aqueous had Cyperus esculentus as a filtration additive, while the others do not contain the additive. The rheological properties, as well as the fluid filtration properties of the drilling muds, were investigated and compared with standard drilling mud. To ascertain validity, the results obtained were validated with the classic filtration model to ensure fit. Results obtained showed that the formulated mud systems had rheological properties that favored the suspension and transportation of drill cuttings, as well as the prevention of flocculation and clogging of drill strings. The rheological properties also showed a progressive trend as the concentrations of the additive were increased from 2 to 8 ppb. It was also further observed from the API and HPHT filter press test that the increase in the concentration of the additive exhibits a progressive trend that can be compared with the standard. In addition, it was observed from the classic filtration model that the experimental results from both mud systems were fit for the adopted model.
Open Access
A proposed simpilfied technique for accurate calculation of flared gas volume: Case study of an oil and gas processing plant in Niger Delta
(Society of Scientific Research, 2015) Igwilo, Kevin; Abonyi, Chukwunonoso; Umeh, Ebuka
A simplified technique for an accurate calculation of flared gas volume has been established. Although the regulatory agencies in the oil and gas industry has placed some financial and cost measures to minimize the amount of standard cubic feet of gas flared per day by operating companies yet some operators and contractors could not keep an accurate measurement on the actual amount of gas flare from their production facilities. These shortcomings are partially caused due to lack of technologies, equipment malfunctions, equipment inefficiencies, human resource deficiencies. However, gas flaring is by no means a simple measurement process on its own. This is primarily due to the large variations in conditions often found in a flare stack. Measurement difficulties could also arise through the flare type based on changes in the flow profile and Reynolds number caused by variation in the physical properties of the gases and errors due to installation effects. From the aforementioned points, it is clear that the accurate measurement of the flared gas is a rigorous and complex process with several challenges to be considered. This paper presents a technique for measuring flared gas volume based on PVs (pressure valves) present in process plants. A similar approach has been applied in South Pars gas development projects in Iran; utilizing the design information in PVs datasheet as well as actual plant data for opening percentage values which have been utilized from plant Distributed Control System (DCS ) and PIMS ( Plant Integrated Management System) via excel and visual basic.5 However, in this study, a new/robust software program that has the ability of extracting data from the plant DCS and PIMS server has been developed using Java, correlation used by this software was generated using Hysys for a particular process plant model in Niger-Delta and the correlation was regressed using excel. An iteration time-step of 1440 minutes has been chosen for greater accuracy. Features of this program include flexibility, less run-time error, user friendly, less memory space and real-time. Assumptions made during these calculations were stated clearly in this paper. Key inputs to this program are valve percentage openings per minute. Key outputs are average percentage opening per day and amount of flared per day in million standard cubic feet (MMscf).
Open Access
Evaluation of the effects of alcohol on de-emulsification of Niger Delta crude oil using commercial de-emulsifiers
(Scientific Research Publishing, 2017-07-14) Igwilo, K. C.; Okolie, S. T. A.; Anawe, P. A. L.; Ogbudu, Roland; Odo, Jude
This research work evaluates the effects of alcohol on de-emulsification of Niger Delta crude oil using RP6000 and Chimec 2439 as de-emulsifiers. The laboratory measurements were carried out as per API standard. Stable emul sion was prepared using brine. The samples were de-emulsified. Methanol and ethanol were added respectively, with water and without water as modifiers. The measurements of the effect of adding alcohols on water separation effi ciency were carried out using methanol to water ratio, M = 4:1 and ethanol water ratio, E = 4:1. The results show that solubility with alcohol is greater in emulsion than the solubility of alcohol without water. Some comparisons were also made based on the plots on percent water separation versus time for the two modifiers and de-emulsifiers. The maximum separation efficiency of 61% was obtained at concentration of 25% methanol, 75% RP6000, 20 ppm and Chimec 2439 gave maximum separation efficiency of 56.6% at concentration of 75%, 20 ppm at 120 minutes. Based on the results, methanol therefore gave larger effect on water separation efficiency than ethanol
Open Access
Radiological and toxicity risk exposures of oil based mud: Health implication on drilling crew in Niger Delta
(Springer-Verlag, 2020) Okoro, Emmanuel Emeka; Ochonma, Chidiebere; Omeje, Maxwell; Sanni, Samuel E.; Emetere, Moses E.; Orodu, Kale B.; Igwilo, Kevin C.
Naturally occurring radioactive materials (NORMs) and the presence of toxic metals in drilling fluids/their additives have raised research interests in recent times owing to the risks associated with the exposure times for drillers of petroleum wells. In this study, two drilling fluids A and B were formulated, while two other Mud Samples C and D were obtained from drilled shale and shale-sand formation zones. All four fluids were collected and analyzed for the presence of radioactive and heavy metals. Lead (Pb), mercury (Hg), cadmium Cd), zinc (Zn), chromium (Cr), aluminum (Al), arsenic (As), nickel (Ni), and copper (Cu) were detected in the mud samples. The heavy metal contents of the mud samples are in the following decreasing order of magnitude Hg>Pb>Cd>Cr.InSamplesA–D,Hg,Pb,Cr,andCdwerefoundtohavesignificantconcentrations,andtheconcentrations of these metals increased in the mud samples after they were used for drilling. The concentration of Hg was above the permissible limit. Also, the concentrations of Pb, Cu, As, and Al found in Mud Samples A and B can cause skin irritations over long-term exposures, while Cd, Hg, Zn, and Ni present in the samples were within levels that can cause lung infections or immune breakdown when ingested over long periods. The quantities of Cd, Hg, and Cu detected in Mud Samples C and D can cause skin irritations over long-term exposures, while those of As, Zn, Ni, and Al were seen to have the potential to cause dermal infections/diseases. Based on the results obtained, the cancer risk for the drilling crew lies within 1.1 × 10−3-7.7×10−3 HQ. The highest dose rate, radium release, and external hazard index were obtained for Mud Sample C whose radium equivalent was judged to be far below the critical safe limit for the drillers. The radium equivalent activity for the two field mud samples (C and D) were estimated to be 27.467 and 22.978 Bq kg−1, respectively, which is the maximum activity obtained for the analyzed samples. The maximum radium equivalent activity for Mud Sample C was estimated as 27.48 Bq kg−1 with a corresponding external hazard index of 0.7. Based on the analysis, there is a significant correlation between the concentration of heavy metals and the radionuclides found in the mud samples.
Open Access
Loss circulation prevention during drilling operation - risk analysis approach and its implications
(Trans Tech Publications Ltd., 2020) Okoro, Emmanuel E.; Okafor, Ikechukwu S.; Igwilo, Kevin C.; Orodu, Kale B.; Dosunmu, Adewale
Drilling engineers and operators are stuck with challenges associated with loss circulation of drilling fluids in wellbores during drilling operation. At such times, a clear and careful decision is required in order to minimize cost or save resources that would have been lost in the bid to remedy the situation. This then informs the need to deploy reliable tools that will inform useful decisions as drawn from a thorough risk-analysis coined from the information gathered from the formation characteristics and operating pressure. In this study, a real-time statistic based approach was adopted in carrying out risk-evaluation of loss circulation events in a wellbore. Based on the expected opportunity loss analysis, it is often non-negotiable to consider other options when the analytical solution suggests that the well should be “abandoned”. For the decision tree, at the decision node, D1, the expected loss of the seal off zone option is $161.25, the expected loss of the drill ahead option is .2 and the expected loss of the abandon option is $13.2. Since the expected loss of the abandon option is less than the expected value of both the seal off and the drill ahead option, it is recommended to abandon the well. Furthermore, the risk analysis proved to be a veritable tool considering the cost implications of other options; and can also serve as basis for automated decision-making.
Open Access
Prediction and analysis of variable parameters of some established models in batch beer fermentation
(U. P., 2019) Kamalu, C. I. O.; Onuoha, O. E.; Uzondu, F. N.; Effiong, E. E.; Obibuenyi, I. J.; Onyelucheya, O. E.
Abstract:In this work, established models of renowned scholars in fermentation technology are analytically solved. Fermentation experiments were also performed on the production of ethanol and biomass from substrate (grain i.e. malted barley) with time and used to validate the analytical solutions of the scholarly models. The result shows that the models were real and true to life as they gave coefficient of correlation of 99.63%. It is also observed that during this fermentation, there was serious interaction between substrate concentration and ethanol concentration, substrate concentration and biomass concentration. From this model, it was found that the yield of ethanol (product) was 79.34%, yield of biomass was 43.8%, initial ethanol before fermentation was 1.45g/lit. Substrate at the beginning, S0= 8.114g/lit. and initial biomass X0 was 0.8098g/lit. This result can be applied in fermentation planning in any brewing company of research centers to predict variation of certain parameters.