Browsing by Author "Igwilo, Kevin C."

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    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.
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    Measurement of the best Z-factor correlation using gas well Inflow performance data in Niger-Delta
    (Research India Publications, 2017) Okoro, Emeka Emmanuel; Dike, Honfre; Igwilo, Kevin C.; Mamudu, Angela
    Gas compressibility has a long and important history for gas industries. The use of z-factor in real gas analysis is unavoidable; hence study of the effects of different z-factor correlations against real life data was carried out. This research establishes the need and a solution for a simple, robust and flexible technique requiring the use of different z-factor correlations. The most common sources of z-factor values are experimental measurement, equations of state method and empirical correlations. Necessity arises when there is no available experimental data for the required composition, pressure and temperature conditions. Presented here is a technique to predict z-factor values using Gas Well Inflow Performance data. The three gas correlations under study are Hall and Yarborough, Dranchuk, Abu and Kassem and Dranchuk, Purvis and Robbinson. The interest of the research was to show the best Z-Factor correlation for Niger Delta. The method or approach used was to review existing models, developed a computer program to evaluate numerically the three correlations and the best correlation is shown by running a statistical absolute average error for each of the calculated gas well performance against the history inflow performance data. Based on the study analysis performed using the Niger-Delta, the Hall and Yarborough is ranked first, followed by Dranchuk￾purvis-Robbinson, while Dranchuk-Abu-Kaseem is recorded the last in the ranking model. Based on this study, it is recommended that the Hall and Yarborough gas deviation model is the best model for Niger Delta.
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    Modification of waste tire pyrolytic oil as base fluid for synthetic lube oil blending and production: Waste tire utilization approach. Journal of Material Cycles and Waste Management (Online First)
    (Springer, 2020) Okoro, Emmanuel E.; Erivona, Nehemiah O.; Sanni, Samuel E.; Orodu, Kale B.; Igwilo, Kevin C.
    This study provides an environmentally friendly process for the production of waste tire pyrolytic oil from fast pyrolysis for use in lube oil production. The produced waste tire pyrolytic oil was further distilled to provide an almost pure base fuid for production of lube oil. The distilled pyrolytic oil was further transformed to lube oil via polyol synthesis. Characterization of the distilled pyrolytic oil from waste tire pyrolysis shows that the oil after distillation contained 2.04 g/100 g of Aliphatic hydrocarbons, 1.96 g/100 g of naphthalene, and 5.99 g/100 g of parafn. The synthetic base fuid was blended with additive to obtain the desired lube oil. Based on the results obtained, the properties of the produced lubricant fall within the accept able criteria for standard lube oils/commercial lubricants. Six diferent blends (A–F) were produced using varied percentages of the selected additives and the base fuid, however, sample C gave the best lube oil blend considering its average density (0.97 kg/L), average viscosity which compares favourably with ISO viscosity (68 mm2/s) of class 68 oil at 40 °C with a fash point above 200 °C
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    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.
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    Reduction in annualar pressure loss by mud rheology control -a means of mud pump pressure control optimization: A case study of Niger Delta well
    (International Knowledge Press, 2016-02-18) Onugha, Ifeyinwa N.; Igwilo, Kevin C.; Duru, Ugochukwu I.
    This paper proposes two linear mathematical models for the reduction of annular pressure loss in a Niger Delta well- X, so that mud pump pressure is optimized. Data related to mud rheology, mud pump pressure, drill cuttings and the well geometry is available for well X which has already been drilled. The first linear model involves the reduction in pressure drop in the drill collar-casing annulus and the second linear model involves the reduction in pressure drop in the drill pipe-casing annulus. These models express reduced or critical annular pressure drops in terms of two mud rheological parameters- the yield point and plastic viscosity. For combined annular drill collar and drill pipe pressure loss, this paper proposes that the two linear mathematical models can be solved simultaneously to obtain optimum yield point and plastic viscosity of the drilling mud system to be employed for hole cleaning in the combined drill collar-casing and drill pipe-casing annulus. The Herschel Bulkley model is employed as the rheological model that represents the properties of the drilling mud system analyzed and is generated for eight rheological cases each of the drill collar and drill pipe annular hole cleaning as well as two cases of the combined drill collar and drill pipe annular hole cleaning.
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    ItemOpen Access
    Reduction in annular pressure loss by mud rheology control-a means of mud pump pressure optimization: A case study of Niger Delta well
    (International Knowledge Press, 2016-02-18) Onugha, Ifeyinwa N.; Igwilo, Kevin C.; Duru, Ugochukwu I.
    This paper proposes two linear mathematical models for the reduction of annular pressure loss in a Niger Delta well- X, so that mud pump pressure is optimized. Data related to mud rheology, mud pump pressure, drill cuttings and the well geometry is available for well X which has already been drilled. The first linear model involves the reduction in pressure drop in the drill collar-casing annulus and the second linear model involves the reduction in pressure drop in the drill pipe-casing annulus. These models express reduced or critical annular pressure drops in terms of two mud rheological parameters- the yield point and plastic viscosity. For combined annular drill collar and drill pipe pressure loss, this paper proposes that the two linear mathematical models can be solved simultaneously to obtain optimum yield point and plastic viscosity of the drilling mud system to be employed for hole cleaning in the combined drill collar-casing and drill pipe-casing annulus. The HerschelBulkley model is employed as the rheological model that represents the properties of the drilling mud system analyzed and is generated for eight rheological cases each of the drill collar and drill pipe annular hole cleaning as well as two cases of the combined drill collar and drill pipe annular hole cleaning