Browsing by Author "Orodu, Kale B."

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    Determining the optimum concentration of multiwalled carbon nanotubes as filtrate loss additive in field‑applicable mud systems
    (Springer, 2019) Okoro, Emeka E.; Zuokumor, Anita A.; Okafor, Ikechukwu S.; Igwilo, K, C.; Orodu, Kale B.
    In a bid to combat fluid loss in muds where the effects of high downhole temperatures have pronounced effects on conventional fluid loss additives, several materials have over time been evaluated. One of such materials is the multiwalled carbon nanotubes (MWCNTs). Most studies in the literature limit the scope of their investigation to how the MWCNT affects mud rheology when added in minute concentrations (0.01–1 ppb). In this study, however, the performance of high concentrations (0.5–3 ppb) of multiwall carbon nanotubes as fluid loss control additives in field-applicable mud systems was put to the test. The essence was to establish an optimal concentration useful for field applications. The degree to which the introduction of varying concentrations of the MWCNT altered the muds capacity to control filter loss was the cardinal areas evaluated. The following are the major outcomes of the experimental study: The plastic viscosity, the yield point and the gel strengths showed a progressive increase as the concentration of the MWCNT in the mud increased for both the water- and oil-based muds. However, an optimum concentration of 2 ppb was observed for the water-based mud. For the filter loss tests on the oil-based mud, the results indicate that low concentrations (0.5 ppb) of the MWCNT led to high filter loss volumes (15 ml), but an increase up to 2.5 ppb reduced the margin of the filter loss volume by 52% (7 ml) from the initial value and a 50% decrease for the standard case. In the case of the water-based mud, equivalent amounts of MWCNT recorded less fluid loss than the standard. A moderately hard and firm cake was reported for all concentrations of the standard and MWCNT for the water- and oil-based muds; however, their cake thickness values were 2 mm and 1 mm for the water- and the oil-based muds, respectively
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    ItemOpen 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.
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    ItemOpen Access
    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.