Research Paper
Volume 5, Issue 3 , July 2016
Research Paper
Seyed Ehsan Eshraghi; Mohammad Reza Rasaei; Peyman Pourafshary; Amir Salar Masoumi
Abstract
Tedious calculations and simulations are needed to obtain an efficient production scenario and/orproper field development strategy. Capacitance-resistance model (CRM) is proved to be a fastreservoir simulation tool using just the field-available data of production and injection rates. Thisapproach sets ...
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Tedious calculations and simulations are needed to obtain an efficient production scenario and/orproper field development strategy. Capacitance-resistance model (CRM) is proved to be a fastreservoir simulation tool using just the field-available data of production and injection rates. Thisapproach sets a time-constant and a weighting factor (or well-pair connectivity parameter) betweeneach pair of injection and production wells according to their histories. In this study, we investigatedthe behavior of the CRM parameters in synthetic reservoir models with different porosity andpermeability maps. Four reservoirs are considered with different porosities and permeabilities to studytheir effects on CRM response. We defined a new parameter, named error to mean production ratio(EMPR), to analyze the CRM performance. Some fluctuations are exerted on the production data toevaluate the capability of CRM against variable production records. Porosity showed a stronger effecton CRM parameters than the permeability based on the calculated EMPR. Unstable productionhistory would result in large error which can be corrected with some smoothing techniques onvariable production data. Also, a linear trend of EMPR was obtained with the change of porosity andpermeability or a combination of the two parameters within the reservoir.
Research Paper
Elham Mortazavi; Mohsen Masihi; Mohammad Hosein Ghazanfari
Abstract
In this study, a chemical additive made by a combination of polymer, alkaline, and silica nanoparticles is used to control the oil recovery and relative permeability curves. Various parametersincluding the type and concentration of polymer, alkaline, and nanosilica particles have been studied.To evaluate ...
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In this study, a chemical additive made by a combination of polymer, alkaline, and silica nanoparticles is used to control the oil recovery and relative permeability curves. Various parametersincluding the type and concentration of polymer, alkaline, and nanosilica particles have been studied.To evaluate the efficiency of these additives, we performed unsteady state displacement experimentsunder the JBN method and determined the pressure gradient across the core samples. Theexperimental observations emphasized that by using the appropriate chemical additives the relativepermeability of the phases is changed towards higher oil relative permeability values, which results inthe oil recovery. The results of this study can improve the chemical flooding for heavy oil recovery.
Hadi Zareei; Mohammadreza Khosravi Nikou; Ahmad Shariati
Abstract
A consequence analysis was performed in one of the gas refineries in Iran to investigate the risks andpotential losses resulted from accidents. Specifically, the consequences of an explosion in LPGspherical tanks were modeled using PHAST and MATLAB software. In this paper, three methods ofcalculation ...
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A consequence analysis was performed in one of the gas refineries in Iran to investigate the risks andpotential losses resulted from accidents. Specifically, the consequences of an explosion in LPGspherical tanks were modeled using PHAST and MATLAB software. In this paper, three methods ofcalculation of PHAST software TNT, multi-energy, and BST were used. The results showed thatmulti energy method is the best method to evaluate overpressure. It was 0.150 bar and 0.159 bar in adistance of 1000 m far from the blast using PHAST and MATLAB respectively. This overpressurecan damage a wall with 30 cm thickness. It also affects the human threshold (1%) ruptured eardrum.Finally, it was found that 100% lethality in a minute happened at 285.5 m and 37.5 kW/m2 when theexplosion happened.
Research Paper
Hojat Ansarinasab; Mahmoud Afshar; Mehdi Mehrpooya
Abstract
In this paper, exergy and exergoeconomic analysis is performed on the recently proposed process forthe coproduction of liquefied natural gas (LNG) and natural gas liquids (NGL) based on the mixedfluid cascade (MFC) refrigeration systems, as one of the most important and popular natural gasliquefaction ...
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In this paper, exergy and exergoeconomic analysis is performed on the recently proposed process forthe coproduction of liquefied natural gas (LNG) and natural gas liquids (NGL) based on the mixedfluid cascade (MFC) refrigeration systems, as one of the most important and popular natural gasliquefaction processes. To carry out this analysis, at first, the proposed process is simulated, and thenthe exergy analysis of the process equipment is performed; finally, an economic model is used for theexergoeconomic analysis. The results include cost of exergy destruction, exergoeconomic factor,exergy destruction, and exergy efficiency. The results of the exergy analysis demonstrate that theexergy efficiency of the proposed process is around 53.83%, and its total exergy destruction rate is42617.5 kW at an LNG and NGL production rates of 68.99 kg/s and 27.41 kg/s respectively. Theresults of exergoeconomic analysis indicate that the maximum exergoeconomic factor, which is69.53%, is related to the second compressor in the liquefaction cycle and the minimumexergoeconomic factor, which is 0.66%, is related to the fourth heat exchanger in the liquefactioncycle. In this process, demethanizer tower holds the highest relative cost difference (100.78) and thefirst air cooler in liquefaction cycle has the lowest relative cost difference (1.09). One of the mostimportant exergoeconomic parameters is the cost of exergy destruction rate. The second heatexchanger has the highest exergy destruction cost (768.91 $/Gj) and the first air cooler in theliquefaction cycle has the lowest exergy destruction cost (19.36 $/Gj). Due to the high value of fuelcost rate (as defined in exergoeconomic analysis) in heat exchangers, their exergy destruction cost ismuch higher than other devices.
Research Paper
Fatemeh Amin; Ali Reza Solaimany Nazar
Abstract
The Taguchi design of experiments (DOE) approach is adopted here to evaluate the impact ofeffective factors such as nanoparticles type, nanoparticles to model solution mass ratio, asphaltenestructure, and temperature on asphaltene adsorption equilibrium. Herein, the toluene-asphaltenesolution model is ...
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The Taguchi design of experiments (DOE) approach is adopted here to evaluate the impact ofeffective factors such as nanoparticles type, nanoparticles to model solution mass ratio, asphaltenestructure, and temperature on asphaltene adsorption equilibrium. Herein, the toluene-asphaltenesolution model is applied. Three commercially nanoparticles (SiO2, Al2O3, and TiO2) are used.Asphaltene characterizations are carried out by X-ray diffraction (XRD) analysis. It is found that thenanoparticle type and asphaltene structure with a respective influence of 48.5% and 3.11% have themaximum and minimum contribution on the amount of adsorbed asphaltene at the selected levelsrespectively. Aluminum oxide nanoparticle has the maximum and silicon oxide nanoparticle showsthe minimum adsorption. The temperature has no statistical significance. Asphaltenes with higheraromaticity have more tendencies for adsorption on nanoparticles.
Research Paper
Hamid Rahmati; Farzad Mahboobi
Abstract
In some engineering fields, wear resistance and a low friction coefficient are required at the sametime. In this research, PTFE nanoparticles and carbon nanotubes were co-deposited within Ni-Pmatrix to obtain an Ni-P-PTFE-CNT hybrid coating for wear resistance and a low friction coefficient.The tribological ...
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In some engineering fields, wear resistance and a low friction coefficient are required at the sametime. In this research, PTFE nanoparticles and carbon nanotubes were co-deposited within Ni-Pmatrix to obtain an Ni-P-PTFE-CNT hybrid coating for wear resistance and a low friction coefficient.The tribological properties of the deposits were evaluated by pin on disc tribometer. The morphologyof the coatings and worn surface was evaluated by scanning electron microscopy. However, theresults showed that the addition of PTFE nanoparticles to the Ni-P electroless coating caused thefriction coefficient to decrease to values lower than 0.2, which led to an improvement in frictionbehavior because of its self-lubricity properties; it, however, decreased the strength of coating due topolymeric and soft structure of the molecules. The simultaneous incorporation of PTFE nanoparticlesand carbon nanotubes can provide the properties of both molecules and increased the strength ofcoating with a low friction coefficient and self-lubricity properties. Therefore, the wear rate and thedegradation of surface were decreased during the wear process.
Research Paper
Volume 5, Issue 3 , July 2016, Pages 82-87