The Experts below are selected from a list of 330 Experts worldwide ranked by ideXlab platform
Amir H Mohammadi - One of the best experts on this subject based on the ideXlab platform.
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A corresponding states-based method for the estimation of natural Gas Compressibility factors
Journal of Molecular Liquids, 2016Co-Authors: Arash Kamari, Amir H Mohammadi, Farhad Gharagheizi, Deresh RamjugernathAbstract:Abstract In this communication, a corresponding states-based model for the calculation/estimation of the Gas Compressibility factor ( z -factor) of natural Gasses is proposed. The method applies the gene expression programming (GEP) algorithm. The parameters of the new model comprise the pseudo-reduced pressure and pseudo-reduced temperature. For assessing the performance and accuracy of the developed model, several statistical and graphical error analyses have been applied simultaneously. Additionally, comparisons have been made between this method and the most widely-used correlations and equations of state (EoS) available in the literature. Various statistical parameters are also used to evaluate the validity and the predictive capability of the newly developed method. Furthermore, the Leverage approach (Williams plot) is used to determine the realm of prediction capability of the new z-factor model and to detect any probable erroneous data points. The results obtained demonstrate that the newly proposed model is more reliable and more effective than the empirical models and EoS methods for prediction of z -factors of natural Gasses.
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application of wilcoxon generalized radial basis function network for prediction of natural Gas Compressibility factor
Journal of The Taiwan Institute of Chemical Engineers, 2015Co-Authors: Mohammadhadi Shateri, Abdolhossein Hemmatisarapardeh, Shohreh Ghorbani, Amir H MohammadiAbstract:Gas Compressibility factor is necessary in most of chemical and petroleum engineering calculations. Accurate and fast calculation of this property is of a vital importance in a large number of simulators used in petroleum and Gas engineering. In this study, a large data bank (978 data points), covering a wide range of natural Gases, was collected from open literature sources. Afterwards, one of the newest and most powerful modeling approach, namely Wilcoxon generalized radial basis function network (WGRBFN) was employed to predict the Compressibility factor of natural Gases. The results obtained from the proposed model were compared to those of nine empirical correlations and five equations of state. Statistical and graphical error analyses demonstrated that the developed model can satisfactorily predict the Compressibility factor of natural Gases with an average absolute percent relative error of 2.3%. Moreover, it was demonstrated that the proposed model outperforms all of the studied empirical correlations and equations of state. Finally, to identify the probable outliers the Leverage approach was performed. All of the experimental data seem to be reliable except 2%. Therefore, the developed model is reliable for the prediction of natural Gas Compressibility factor in its applicability domain.
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efficient estimation of natural Gas Compressibility factor using a rigorous method
Journal of Natural Gas Science and Engineering, 2014Co-Authors: Amir Fayazi, Milad Arabloo, Amir H MohammadiAbstract:Abstract The Compressibility factor (Z-factor) of natural Gases is necessary in many Gas reservoir engineering calculations. Accurate determination of this parameter is of crucial need and challenges a large number of used simulators in petroleum engineering. Although numerous studies for prediction of Gas Compressibility factor have been reported in the literature, the accurate prediction of this parameter has been a topic of debate in the literature. For this purpose, a new soft computing approach namely, least square support vector machine (LSSVM) modeling optimized with coupled simulated annealing optimization technique is implemented. The model is developed and tested using a large database consisting of more than 2200 samples of sour and sweet Gas compositions. The developed model can predict the natural Gas Compressibility factor as a function of the Gas composition (mole percent of C1–C7+, H2S, CO2, and N2), molecular weight of the C7+, pressure and temperature. The calculated Z-factor values by developed intelligent model are also compared with predictions of other well-known empirical correlations. Statistical error analysis shows that the developed LSSVM model outperforms all existing predictive models with average absolute relative error of 0.19% and correlation coefficient of 0.999. Results from present study show that implementation of LSSVM can lead to more accurate and reliable estimation of natural Gas Compressibility factor.
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Prediction of sour Gas Compressibility factor using an intelligent approach
Fuel Processing Technology, 2013Co-Authors: Arash Kamari, Abdolhossein Hemmati-sarapardeh, Seyed-morteza Mirabbasi, Mohammad Nikookar, Amir H MohammadiAbstract:Abstract Compressibility factor ( z -factor) values of natural Gasses are essential in most petroleum and chemical engineering calculations. The most common sources of z -factor values are laboratory experiments, empirical correlations and equations of state methods. Necessity arises when there is no available experimental data for the required composition, pressure and temperature conditions. Introduced here is a technique to predict z -factor values of natural Gasses, sour reservoir Gasses and pure substances. In this communication, a novel mathematical-based approach was proposed to develop reliable model for prediction of Compressibility factor of sour and natural Gas. A robust soft computing approach namely least square support vector machine (LSSVM) modeling optimized with coupled simulated annealing (CSA) optimization tool was proposed. To evaluate the performance and accuracy of this model, statistical and graphical error analyses have been used simultaneously. Moreover, comparative studies have been conducted between this model and nine empirical correlations and equations of state. The obtained results demonstrated that the proposed CSA-LSSVM model is more robust, reliable and efficient than the existing correlations and equations of state for prediction of z -factor of sour and natural Gasses.
Yong Tang - One of the best experts on this subject based on the ideXlab platform.
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measurement and correlation of Compressibility factor of high co2 content natural Gas
Journal of Petroleum Science and Engineering, 2012Co-Authors: Xiaoqiang Bian, Yong TangAbstract:Abstract The JEFRI-PVT apparatus made in Canada by the Schlumberger company has been used to obtain accurate Compressibility factor measurements on high CO 2 -content natural Gasses so as to study the effect of different CO 2 content on Gas Compressibility factor (range covered: temperature, 263.15 K to 313.15 K; pressure, 3 MPa to 15 MPa; CO 2 content, 9.84, 28.86 and 50.99 mol%). The results showed that Gas Compressibility factors reduce with increasing CO 2 content in natural Gasses and increase with increasing temperature. In addition, a non-integral power polynomial correlation was proposed without an iterative procedure whose coefficients were determined by fitting experimental data. The mixing rules used include: Kay's mixing rule combined with Wichert-Aziz correlations (Kay) and Stewart-Burkhardt-Voo mixing rule with Wichert-Aziz (SBV). Comparison of the DAK-SBV, DAK-Kay, and proposed correlations showed that the presented model yielded the most accurate predictions with the lowest average absolute deviation (0.42%) among them.
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experimental determination and prediction of the Compressibility factor of high co2 content natural Gas with and without water vapor
Journal of Natural Gas Chemistry, 2011Co-Authors: Xiaoqiang Bian, Zhimin Du, Yong TangAbstract:Abstract In order to study the effect of different CO 2 contents on Gas Compressibility factor (Z-factor), the JEFRI-PVT apparatus has been used to measure the Z-factor of dry natural Gas with CO 2 content range from 10.74 to 70.42 mol% at the temperature range from 301.2 to 407.3 K and pressure range from 7 to 44 MPa. The results show that Z-factor decreases with increasing CO 2 content in natural Gas at constant temperature and increases with increasing temperature for natural Gas with the same CO 2 content. In addition, the Z-factor of water-saturated natural Gas with high CO 2 content has been measured. A comparison of the Z-factor between natural Gas with and without saturated water vapor indicates that the former shows a higher Z-factor than the latter. Furthermore, Peng-Robinson, Hall-Yarborough, and Soave-Benedict-Webb-Rubin equations of state (EoS) are used for the calculation of Z-factor of high CO 2 content natural Gas with and without water vapor. The optimal binary interaction parameters (BIP) for PR EoS are presented. The measured Z-factor is compared with the calculated Z-factor based on three models, which shows that PR EoS combined with van der Waals mixing rule for Gas without water and Huron-Vidal mixing rule for water-saturated Gas, are in good agreement with the experimental data.
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Experimental determination and prediction of the Compressibility factor of high CO2 content natural Gas with and without water vapor
Journal of Natural Gas Chemistry, 2011Co-Authors: Xiaoqiang Bian, Yong TangAbstract:Abstract In order to study the effect of different CO 2 contents on Gas Compressibility factor (Z-factor), the JEFRI-PVT apparatus has been used to measure the Z-factor of dry natural Gas with CO 2 content range from 10.74 to 70.42 mol% at the temperature range from 301.2 to 407.3 K and pressure range from 7 to 44 MPa. The results show that Z-factor decreases with increasing CO 2 content in natural Gas at constant temperature and increases with increasing temperature for natural Gas with the same CO 2 content. In addition, the Z-factor of water-saturated natural Gas with high CO 2 content has been measured. A comparison of the Z-factor between natural Gas with and without saturated water vapor indicates that the former shows a higher Z-factor than the latter. Furthermore, Peng-Robinson, Hall-Yarborough, and Soave-Benedict-Webb-Rubin equations of state (EoS) are used for the calculation of Z-factor of high CO 2 content natural Gas with and without water vapor. The optimal binary interaction parameters (BIP) for PR EoS are presented. The measured Z-factor is compared with the calculated Z-factor based on three models, which shows that PR EoS combined with van der Waals mixing rule for Gas without water and Huron-Vidal mixing rule for water-saturated Gas, are in good agreement with the experimental data.
Vyacheslav Akkerman - One of the best experts on this subject based on the ideXlab platform.
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analytical study of an effect of Gas Compressibility on a burning accident in an obstructed passage
Physics of Fluids, 2020Co-Authors: Furkan Kodakoglu, Vyacheslav AkkermanAbstract:The incompressible analytical formulation describing a burning accident in an obstructed passage [F. Kodakoglu et al., “Towards descriptive scenario of a burning accident in an obstructed mining passage: An analytical approach,” in 27th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS), Beijing, China, July 28–Aug 2, 2019, Paper 369] is extended to account for Gas compression, which cannot be ignored as soon as the flame velocity starts approaching the speed of sound. The analysis combines the theories of globally spherical, self-accelerating premixed expanding flames with that of ultrafast flame acceleration in obstructed conduits. It is shown that while the entire acceleration scenario may promote the flame velocity up to near-sonic values, the effect of Gas Compressibility moderates flame acceleration, and such an impact depends strongly on various thermal-chemical properties of the combustible premixture. Starting with Gaseous combustion, the formulation is subsequently widened to the Gaseous-dusty environments with combustible (coal) and inert (sand) dusts, and their combinations. In particular, it is quantified how the flame evolution and its locus and velocity depend on the type and size of the dust particles.
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influence of Gas Compressibility on a burning accident in a mining passage
Combustion Theory and Modelling, 2018Co-Authors: Sinan Demir, Anish Raman Calavay, Vyacheslav AkkermanAbstract:A recent predictive scenario of a methane/air/coal dust fire in a mining passage is extended by incorporating the effect of Gas Compressibility into the analysis. The compressible and incompressible formulations are compared, qualitatively and quantitatively, in both the two-dimensional planar and cylindrical-axisymmetric geometries, and a detailed parametric study accounting for coal-dust combustion is performed. It is shown that Gas compression moderates flame acceleration, and its impact depends on the type of the fuel, its various thermal-chemical parameters as well as on the geometry of the problem. While the effect of Gas compression is relatively minor for the lean and rich flames, providing 5–25% reduction in the burning velocity and thereby justifying the incompressible formulation in that case, such a reduction appears significant, up to 70% for near-stoichiometric methane–air combustion, and therefore it should be incorporated into a rigorous formulation. It is demonstrated that the flame tip v...
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influence of Gas compression on flame acceleration in the early stage of burning in tubes
Combustion and Flame, 2013Co-Authors: Damir Valiev, Vyacheslav Akkerman, Larserik Eriksson, M Kuznetsov, Vitaly BychkovAbstract:The mechanism of finger flame acceleration at the early stage of burning in tubes was studied experimentally by Clanet and Searby [Combust. Flame 105 (1996) 2251 for slow propane-air flames, and elucidated analytically and computationally by Bychkov et al. [Combust. Flame 150 (2007) 2631 in the limit of incompressible flow. We have now analytically, experimentally and computationally studied the finger flame acceleration for fast burning flames, when the Gas Compressibility assumes an important role. Specifically, we have first developed a theory through small Mach number expansion up to the first-order terms, demonstrating that Gas compression reduces the acceleration rate and the maximum flame tip velocity, and thereby moderates the finger flame acceleration noticeably. This is an important quantitative correction to previous theoretical analysis. We have also conducted experiments for hydrogen-oxygen mixtures with considerable initial values of the Mach number, showing finger flame acceleration with the acceleration rate much smaller than those obtained previously for hydrocarbon flames. Furthermore, we have performed numerical simulations for a wide range of initial laminar flame velocities, with the results substantiating the experiments. It is shown that the theory is in good quantitative agreement with numerical simulations for small Gas compression (small initial flame velocities). Similar to previous works, the numerical simulation shows that finger flame acceleration is followed by the formation of the "tulip" flame, which indicates termination of the early acceleration process.
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flame acceleration in channels with obstacles in the deflagration to detonation transition
Combustion and Flame, 2010Co-Authors: Damir Valiev, Vyacheslav Akkerman, Vitaly Bychkov, Larserik ErikssonAbstract:It was demonstrated recently in Bychkov et al. [Bychkov et al., Phys. Rev. Lett. 101 (2008) 164501], that the physical mechanism of flame acceleration in channels with obstacles is qualitatively different from the classical Shelkin mechanism. The new mechanism is much stronger, and is independent of the Reynolds number. The present study provides details of the theory and numerical modeling of the flame acceleration. It is shown theoretically and computationally that flame acceleration progresses noticeably faster in the axisymmetric cylindrical geometry as compared to the planar one, and that the acceleration rate reduces with increasing Mach number and thereby the Gas Compressibility. Furthermore, the velocity of the accelerating flame saturates to a constant value that is supersonic with respect to the wall. The saturation state can be correlated to the Chapman–Jouguet deflagration as well as the fast flames observed in experiments. The possibility of transition from deflagration-to-detonation in the obstructed channels is demonstrated.
Ebrahim Nemati Lay - One of the best experts on this subject based on the ideXlab platform.
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estimation of natural Gas Compressibility factors using artificial neural network approach
Journal of Natural Gas Science and Engineering, 2012Co-Authors: Ehsan Sanjari, Ebrahim Nemati LayAbstract:Abstract Prediction of Compressibility factor of natural Gas is an important key in many Gas and petroleum engineering calculations. In this study Compressibility factors of different compositions of natural Gas are modeled by using an artificial neural network (ANN) based on back-propagation method. A reliable database including more than 5500 experimental data of Compressibility factors is used for testing and training of ANN. The designed neural network can predict the natural Gas Compressibility factors using pseudo-reduced pressure and pseudo reduced temperature with average absolute relative deviation percent of 0.593. The accuracy of designed ANN has been compared to the mostly used empirical models as well as equations of state of Peng–Robinson and statistical association fluid theory. The comparison indicates that the proposed method provide more accurate results relative to other methods used in this work.
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an accurate empirical correlation for predicting natural Gas Compressibility factors
Journal of Natural Gas Chemistry, 2012Co-Authors: Ehsan Sanjari, Ebrahim Nemati LayAbstract:Abstract The Compressibility factor of natural Gas is an important parameter in many Gas and petroleum engineering calculations. This study presents a new empirical model for quick calculation of natural Gas Compressibility factors. The model was derived from 5844 experimental data of Compressibility factors for a range of pseudo reduced pressures from 0.01 to 15 and pseudo reduced temperatures from 1 to 3. The accuracy of the new empirical correlation has been compared with commonly used existing methods. The comparison indicates the superiority of the new empirical model over the other methods used to calculate Compressibility factor of natural Gas with average absolute relative deviation percent (AARD%) of 0.6535.
Mofazzal Hossain - One of the best experts on this subject based on the ideXlab platform.
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Determination of best possible correlation for Gas Compressibility factor to accurately predict the initial Gas reserves in Gas-hydrocarbon reservoirs
International Journal of Hydrogen Energy, 2017Co-Authors: Omar Al-fatlawi, Mofazzal Hossain, Jake OsborneAbstract:Abstract Gas Compressibility factor or z-factor plays an important role in many engineering applications related to oil and Gas exploration and production, such as Gas production, Gas metering, pipeline design, estimation of Gas initially in place (GIIP), and ultimate recovery (UR) of Gas from a reservoir. There are many z-factor correlations which are either derived from Equation of State or empirically based on certain observation through regression analysis. However, the results of the z-factor obtained from different correlations have high level of variance for the same Gas sample under the same pressure and temperature. It is quite challenging to determine the most accurate correlation which provides accurate estimate for a range of pressures, temperatures, and Gas compositions. This paper presents a novel method to accurately estimate GIIP of an Australian tight Gas field through identification of the most appropriate z-factor correlations, which can accurately determine the z-factor and other PVT properties for a wide range of Gas compositions, temperatures, and pressures. The sensitivity study results demonstrated that a single correlation cannot work across the range of pressures and temperatures for a certain Gas sample necessary to calculate z-factor during simulation process and/or other analysis, such as material balance and volumetric estimate.
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a practical method for the evaluation of the joule thomson effects to predict flowing temperature profile in Gas producing wells
Journal of Natural Gas Science and Engineering, 2015Co-Authors: N. Tarom, Mofazzal HossainAbstract:Abstract Accurate evaluation of Joule Thomson Coefficient (JTC) is important for the prediction of flowing temperature profile in a Gas producing well. The evaluation of JTC requires the determination of derivative of Gas Compressibility factor with respect to change in temperature at constant pressure (i.e. (∂Z/∂T)p). This may be determined using an appropriate Equations of States (EOS) for a given Gas mixture where compositions details are known. In many cases, the details of Gas compositions and its associated properties are not known, especially at the appraisal stage. In this study, a simplified practical method has been developed to predict the JTC. This paper presents details of the mathematical model based on which the proposed method is developed. The terms Z and (∂Z/∂T)p have been predicted for a number of Gas mixtures using proposed method, and compared the results with those obtained using Peng–Robinson Equation of State (PR EOS) and HYSYS software to provide the accuracy of this work for evaluation of Compressibility factor for Gas mixtures. The results showed close agreement between two methods. The model is applied to represent Gas field in order to predict the temperature profile for Gas production wells. A sample case study has been carried out to investigate the flowing temperature profile along a Gas producing well. It is demonstrated that the proposed method can be reliably used for evaluation of well following temperature profile along Gas producing wellbores.
