scholarly journals Integrated-reservoir-model-based critical oil rate correlation for vertical wells in thin oil rim reservoirs in the Niger Delta

2018 ◽  
Vol 7 (3) ◽  
pp. 1757
Author(s):  
Anietie Ndarake Okon ◽  
Dulu Appah
Keyword(s):  
Niger Delta ◽  
Sensitivity Study ◽  
Coefficient Of Determination ◽  
Limited Attention ◽  
Optimization Approach ◽  
Reservoir Model ◽  
Vertical Wells ◽  
Chi Square ◽  
Water Coning ◽  
Oil Rim

Thin oil rim reservoirs are mostly characterized by development and production challenges; one of which is early water coning tendency. In the Niger Delta, most developed critical oil rate correlations to avert coning focused on conventional bottom-water drive reservoirs, while thin oil rim reservoirs received limited attention. Available correlations to estimate critical oil rate of thin oil rim reservoirs in Niger Delta are based on generic reservoir models, which does not consider the reservoir heterogeneity. Hence, it leaves these available correlations’ predictions in doubt, considering the sensitive nature of developing thin oil rim reservoirs. Thus, a correlation for critical oil rate (qc) based on integrated reservoir model in the Niger Delta was develop for thin oil rim reservoirs using multivariable numerical optimization approach. The obtained result indicated that the developed correlation predicted 226.05 bbl/day compared to the actual Oilfield critical oil rate of 226.11 bbl/day. Furthermore, sensitivity study indicated that the developed correlation and the integrated reservoir model predictions of fractional well penetration (hp/h) and height below perforation - oil column (hbp/h) on critical oil rate (qc) were close and resulted in coefficient of determination (R2) of 0.9266 and 0.9525, Chi square (X2) of 0.539 and 0.655, and RMSE of 4.336 and 4.357. Additionally, the results depict that critical oil rate depends indirectly on fractional well penetration and directly on height above perforation for vertical wells. Therefore, to delay water-coning tendency in thin oil rim reservoirs these completion parameters are consideration in vertical wells to establish optimum critical oil rate during hydrocarbons production. Also, the developed correlation can be used as a quick tool to estimate critical oil rate of thin oil rim reservoirs in the Niger Delta.  

scholarly journals Correlation for Predicting Water Breakthrough Time in Thin Oil Rim Reservoirs in the Niger Delta

2018 ◽  
Vol 6 (3) ◽  
Author(s):  
Anietie Okon ◽  
Dulu Appah ◽  
Julius Akpabio
Keyword(s):  
Production Rate ◽  
Oil Recovery ◽  
Niger Delta ◽  
Oil Production ◽  
Coefficient Of Determination ◽  
Reservoir Model ◽  
Breakthrough Time ◽  
Well Completion ◽  
Water Breakthrough ◽  
Oil Rim

In the Niger Delta, available correlations to predict water breakthrough time in thin oil rim reservoirs are based on generic reservoir models and/or experimental design approach. This approach had not considered the heterogeneity of the reservoir. Thus, the prediction of these available correlations for thin oil rim reservoirs in the Niger Delta is in doubt, considering the sensitive nature of developing thin oil rim reservoirs. Then, a correlation for water breakthrough time (tbt) was developed based on integrated reservoir model of thin oil rim reservoir in the Niger Delta. The obtained result indicated that the developed correlation predicted 1652.72 days compared to the actual Oilfield breakthrough time of 1653 days (about 4.53 years). Also, sensitivity study showed that the developed correlation and the integrated reservoir model predictions of oil production rate (qo), fractional well penetration (hp/h) and height above perforation-oil column (hap/h) on the water breakthrough time (tbt) were close and resulted in coefficient of determination (R2) of 0.9697, 0.8597 and 0.9553, respectively. Furthermore, the results depicted that water coning breakthrough time (tbt) depends directly on oil production rate (q) and well completion parameters: fractional well penetration (hp/h) and height above perforation (hap). Hence, to delay early water breakthrough in thin oil rim reservoirs, these completion parameters are consideration in vertical wells to achieve optimum oil recovery. Also, the developed correlation can be used as a quick and robust tool to predict water breakthrough time of thin oil rim reservoirs in the Niger Delta.

scholarly journals The effect of chemically enhanced oil recovery on thin oil rim reservoirs

2021 ◽  
Vol 11 (3) ◽  
pp. 1461-1474
Author(s):  
O. A. Olabode ◽  
V. O. Ogbebor ◽  
E. O. Onyeka ◽  
B. C. Felix
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Niger Delta ◽  
Surfactant Concentration ◽  
Base Case ◽  
Production Studies ◽  
Water Alternating Gas ◽  
Water Coning ◽  
Oil Rim

AbstractOil rim reservoirs are characterised with a small thickness relative to their overlying gas caps and underlying aquifers and the development these reservoirs are planned very carefully in order to avoid gas and water coning and maximise oil production. Studies have shown low oil recoveries from water and gas injection, and while foam and water alternating gas injections resulted in positive recoveries, it is viewed that an option of an application of chemical enhanced oil recovery option would be preferable. This paper focuses on the application of chemical enhanced oil recovery to improve production from an oil rim reservoir in Niger Delta. Using Eclipse black oil simulator, the effects of surfactant concentration and injection time and surfactant alternating gas are studied on overall oil recovery. Surfactant injections at start and middle of production resulted in a 3.7 MMstb and 3.6 MMstb at surfactant concentration of 1% vol, respectively. This amounted to a 6.6% and 6.5% increment over the base case of no injection. A case study of surfactant alternating gas at the middle of production gave an oil recovery estimate of 10.7%.

Optimal Performance of the TLCD in Structural Pitching Vibration Control

2002 ◽  
Vol 8 (5) ◽  
pp. 619-642 ◽  
Author(s):  
S. D. Xue ◽  
J. M. Ko ◽  
Y. L. Xu
Keyword(s):  
Numerical Optimization ◽  
Sensitivity Study ◽  
Optimization Approach ◽  
Optimum Control ◽  
Head Loss Coefficient ◽  
Tuning Ratio ◽  
Mass Moment ◽  
Practical Design ◽  
Mass Moment Of Inertia ◽  
Structural Uncertainties

A detailed optimal parametric study is performed for a tuned liquid column damper (TLCD) in suppressing the pitching vibration of structures. Due to the difficulty of finding analytical solutions for the damped structure, a numerical optimization approach is proposed and applied to the system to find the optimum TLCD parameters. The variations of the optimum control parameter with system parameters are determined and discussed. Using various numerical searching data, a set of practical design formulas for the optimum tuning ratio and optimum head loss coefficient of the TLCD are then derived through regression analysis. The comparison between practical design formula and numerical optimization shows a very close agreement between the two results. The practical design formulas provide a convenient tool for designers. In order to account for the possible effects of structural uncertainties, a parametric sensitivity study on the de-tuning of optimum damper parameters is also carried out. It is found that the detuning effect is more severe for low damped structure with lower ratios of mass moment of inertia, especially for the detuning of tuning ratio.

scholarly journals Methods and techniques of research motivation and satisfaction of employees

2021 ◽  
Vol 9 (2) ◽  
pp. 53-63
Author(s):  
Dragana Pešić-Jenačković
Keyword(s):  
Analysis Of Variance ◽  
Employee Motivation ◽  
Test Point ◽  
Coefficient Of Determination ◽  
Business Success ◽  
Chi Square ◽  
Methods And Techniques ◽  
Chi Square Test ◽  
Using Data ◽  
The Impact

Motivation and employee satisfaction are very important precondition for the effectiveness of work and the achievement of set goals for individuals and organizations. Consequently, continuous measurement of employee motivation and satisfaction is essential to improve company's efficiency and improve human resource use. The results of a well-planned, detailed and adequate methods and techniques of research on employee motivation and satisfaction can be applied to the design of various schemes in order to reduce absenteeism and employee turnover and overall business success. In this paper, the emphasis is on the methodology of researching employee motivation and satisfaction. In addition to the elaboration of questionnaires with scales for measuring the motivation and satisfaction of employees, it is explained in which situations, in which types of questions and answers, respectively, types of data, and how certain statistical techniques are applied, such as: T-test, One-factor analysis of variance (ANOVA), Chi-square test, Point-two-series correlations. Also, the importance of using the subsequent post hoc test (LSD comparison) in the analysis of variance, as well as the indicators of correlation, the strength of the impact, such as: phi correlation coefficient, Kramer's coefficient and contingency coefficient, is pointed out in the Chi-square test. In addition to the mentioned techniques and indicators from SPSS, the role of certain indicators (eta squared and coefficient of determination) is calculated, which are calculated using data from research results and with the help of certain formulas

scholarly journals Drying kinetics of crushed mass of ‘jambu’: Effective diffusivity and activation energy

2018 ◽  
Vol 22 (7) ◽  
pp. 499-505 ◽  
Author(s):  
Francileni P. Gomes ◽  
Resende Osvaldo ◽  
Elisabete P. Sousa ◽  
Daneil E. C. de Oliveira ◽  
Francisco R. de Araújo Neto
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Agricultural Research ◽  
Effective Diffusion ◽  
Effective Diffusivity ◽  
Information Criterion ◽  
Drying Kinetics ◽  
Coefficient Of Determination ◽  
Chi Square ◽  
Chi Square Test

ABSTRACT The aim of this paper was to analyze the drying kinetics, test the Akaike information criterion (AIC) and Schwarz’s Bayesian information criterion (BIC) in the selection of models, determine the effective diffusivity and activation energy of the crushed mass of ‘jambu’ leaves for different conditions of temperature and layer thicknesses. The experiment was carried out at the Food Laboratory of the Brazilian Agricultural Research Corporation (Embrapa) in Macapá-AP. Drying was carried out in air circulation oven with speed of 1.0 m s-1 at various temperatures (60, 70 and 80 ºC) and layer thicknesses (0.005 and 0.010 m). The experimental data were fitted to 11 mathematical models. Coefficient of determination (R2), mean relative error (P), mean estimated error (SE), Chi-square test (χ2), AIC and BIC were the selection criteria for the models. For the effective diffusivity, the Fick’s diffusion model was used considering the flat plate geometry. It was found that Midilli and Logarithmic models showed the best fit to the experimental data of drying kinetics. Effective diffusion coefficient increases with increment in the thickness of the material and with the temperature elevation. Activation energy of the material was of 16.61 kJ mol-1 for the thickness of 0.005 m, and 16.97 kJ mol-1 for the thickness of 0.010 m. AIC and BIC can be additionally included to select models of drying.

An Analytical Solution for Water Coning in Vertical Wells

2012 ◽  
Vol 27 (02) ◽  
pp. 195-204 ◽  
Author(s):  
Mohammad Tabatabaei ◽  
Ali Ghalambor ◽  
Boyun Guo
Keyword(s):  
Analytical Solution ◽  
Vertical Wells ◽  
Water Coning

scholarly journals Enhanced sorption capacity of the metal-dye system from water effluents by using polish activated industrial waste

2020 ◽  
Author(s):  
Eleonora Sočo ◽  
Jan Kalembkiewicz
Keyword(s):  
Coal Fly Ash ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Coefficient Of Determination ◽  
Isotherm Models ◽  
Particle Model ◽  
Particle Diffusion ◽  
Hexadecyltrimethylammonium Bromide ◽  
Chi Square ◽  
Chi Square Test

Abstract The activated coal fly ash (FA) treated with NaOH and hexadecyltrimethylammonium bromide (HDTMABr) was used as adsorbent for removal of cadmium(II) ions and rhodamine B (RB) form an aqueous solution. Characterization of FA and FA-HDTMABr were done by using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The sorption equilibrium in the system were analysed by isotherm models, such as Freundlich, Langmuir, generalized Langmiur-Freundlich, Redlich-Peterson, Jovanović, extended Jovanović, Tóth, Fumkin-Fowler-Guggenheim, Fowler-Guggenheim-Jovanović-Freundlich, Temkin, Dubinin-Radushkevich, Halsey, Brunauer Emmett and Teller. The evaluation of fitting of the isotherms studied experimentally points was carried out by means of the reduced chi-square test and the coefficient of determination. The maximum monolayer adsorption capacity of the FA-HDTMABr was found to be 744 mg·g−1 and 666 mg·g−1 for Cd(II) and RB, respectively. The PFO, PSO, Elovich mass transfer, liquid film diffusion and intra-particle diffusion models were analysed. Sorption kinetics data were well fitted by PSO model. The Elovich and intra-particle model also revealed that there are two separate stages in the sorption process, namely, the external diffusion and the inter-particle diffusion.

scholarly journals Evaluation of Government’s Efforts to Mitigate the Adverse Effects of Gas Flaring in Host Communities

2021 ◽  
pp. 42-50
Author(s):  
Nkemdilim I. Obi ◽  
Phillip T Bwititi ◽  
Ezekiel U. Nwose
Keyword(s):  
Gender Differences ◽  
Niger Delta ◽  
Behavioural Change ◽  
Chi Square ◽  
Age And Gender ◽  
Gas Flaring ◽  
Mitigation And Adaptation ◽  
Age And Gender Differences ◽  
And Gender ◽  
Chi Square Tests

Background: This is a 5th in the series on gas flaring in Niger Delta Nigeria and previous reports have highlighted health impact and comparison of communities, amongst others. Government have mitigation programs whose satisfaction in the communities of Niger Delta is unknown. Objective: The objective of this study is to evaluate government’s efforts at mitigation and adaptation whether there are age and/or gender differences Methods: This was a quantitative survey cross-sectional study that used Likert scale questionnaire to generate views of the community on the behavioural change wheel (BCW) as well as mitigation and adaptation efforts of the government. Respondents were stratified into age groups and dichotomized in female or male and analysis involved multivariate analysis (MANOVA) to evaluate age and gender differences. Chi-Square tests were performed to assess associations between BCW components mitigation versus adaptation. Results: A total of 435 respondents were included and the results show levels of inconsistent age and gender differences. Men tended to agree more on government’s BCW albeit not significance achieved, while women agreed more mitigation and adaptation (p < 0.02). On age, the silent generation (>70 years old) group agreed more on BCW, but contrarily disagreed on mitigation and adaptation while younger generation agreed on the latter (0.001). Chi-Square tests show significance for association. Conclusion: This report highlights divergent views of the community on the discourse of government’s efforts at mitigation and adaptation of gas flaring in Niger Delta Nigeria, thereby providing empirical evidence of generational gap on environmental issue.

scholarly journals Thin Layer Drying Kinetics Modelling of Curry Leaves (Murraya koenigii L.) in Cabinet Dryer

2018 ◽  
Vol 2 ◽  
pp. 53-58
Author(s):  
Arjun Ghimire ◽  
Nirajan Magar
Keyword(s):  
Experimental Data ◽  
Thin Layer ◽  
Effective Diffusivity ◽  
Coefficient Of Determination ◽  
Murraya Koenigii ◽  
Small Tree ◽  
Chi Square ◽  
Kinetics Modelling ◽  
Curry Leaves ◽  
Thin Layer Drying

Curry leaves (Murraya koenigii L.) are the sweet smelling leaves of small tree of Rutaceae family native to Southwest Asia. In this study, the effect of temperatures (50, 55 and 60°C) on the drying of curry leaves was investigated. The experimental data were fitted to six thin layer mathematical models (Newton, Page, Handerson and Pabis, logarithmic, two-term exponential and Midilli et al). The models were evaluated in terms of coefficient of determination (R2), chi square (χ2) and root mean square error (RMSE). The Midilli et al model was best fitted to the experimental data of all the models evaluated. The effective diffusivity was calculated using Fick's diffusion equation, and the value varied from 2.07×10-12 m2/s to 2.643×10-12 m2/s. The activation energy and the diffusivity constant were found to be 21.808 kJ/mol and 4.667×10-8 m2/s respectively.

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