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pressure-and-temperature
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Complexity of density dependencies of thermal and internal pressure compared to that of total pressure
, Article Industrial and Engineering Chemistry Research ; Volume 52, Issue 23 , May , 2013 , Pages 8034-8045 ; 08885885 (ISSN) ; Parsafar, G ; Sharif University of Technology
2013
Abstract
A simple equation of state (EoS) has recently been introduced (J. Phys. Chem. B2009, 113, 11977-11987) as (Z - 1)v2 = e + f/ρ + gρ2, where Z ≡ pv/RT is the compressibility factor, v = 1/ρ is molar volume, and e, f, and g are temperature dependent parameters. This EoS has been found to be accurate for all types of nano and bulk solids and bulk fluids, in the entire temperature and pressure ranges for which experimental data are reported, except for the isotherms within 1 ≤ T r = T/Tc ≤ 1.1 for the spherical and near spherical species and for a wider temperature range for the cylindrical molecules. The aim of this work is to investigate the validity of a three-term expression similar to the...
Quasiadiabatic approach for laser-induced single-bubble sonoluminescence
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 85, Issue 1 , 2012 ; 15393755 (ISSN) ; Razeghi, F ; Ebrahimi, H ; Fallahi, S ; Lotfi, E ; Sharif University of Technology
2012
Abstract
The luminescence parameters of laser-induced bubble in the presence of an acoustic field in water are studied. A comparison is made between parameters such as bubble radius, interior temperature, and pressure of the bubble induced by laser and an acoustic field influenced by different driving pressure amplitudes. It is found that the bubble volume induced by laser at the collapse instant is more than 106 times larger than the one induced by an acoustic field. It is also noticed, by increasing the driving pressure amplitude, the bubble radius decreases in both cases, however, the bubble interior pressure and temperature increase
Reversibility of Asphaltene Aggregation in Live Oils: Qualitative and Quantitative Evaluation
, Article Journal of Chemical and Engineering Data ; Volume 60, Issue 9 , August , 2015 , Pages 2646-2654 ; 00219568 (ISSN) ; Rashidi, F ; Mousavi Dehghani, S. A ; Ghazanfari, M. H ; Sharif University of Technology
American Chemical Society
2015
Abstract
Despite the numerous experimental studies concerning asphaltene, the extent of reversibility of asphaltene aggregation at reservoir conditions remains still an elusive and controversial issue in the available literature. In this work, a series of depressurization and repressurization experiments were performed on three different live oils for qualitative and quantitative evaluation of the reversibility of asphaltene aggregation under typical pressure and temperature conditions of oil fields. The obtained results reveal that the kinetics and the extent of reversibility of asphaltene aggregation at elevated pressure and temperature are majorly controlled by the characteristics of the reservoir...
Investigation of effects of salinity, temperature, pressure, and crude oil type on the dynamic interfacial tensions
, Article Chemical Engineering Research and Design ; Volume 115 , 2016 , Pages 53-65 ; 02638762 (ISSN) ; Riazi, M ; Ayatollahi, S ; Sharif University of Technology
Institution of Chemical Engineers
2016
Abstract
The main objectives of this study are to determine the influence of crude oil type, salinity, temperature and pressure on the dynamic interfacial tension (DIFT) of crude oil based on the experiments and modeling approaches. DIFT is also modeled using dynamic adsorption models, mono-exponential decay model as well as empirical equations. The results showed that when temperature increases, unlike deionized water which inversion phase temperature was observed, the equilibrium IFT of crude oils/sea water increases due to reduction of surface excess concentration of natural surfactants at the fluid/fluid interface as a dominant mechanism
An investigation on the flow physics of bubble implosion using numerical techniques
, Article Ocean Engineering ; Volume 153 , 2018 , Pages 185-192 ; 00298018 (ISSN) ; Nasiri, M. M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this paper, implosion of a micron-sized air bubble was studied numerically using OpenFoam software package. Then a parametric investigation on the flow physics of the problem was performed. The results show that as the initial pressure of the liquid increases, the pressure and the temperature inside the bubble increases such that in some cases, the temperature is as high as the one required for luminescence. Also, increasing the density and the temperature of the liquid solely, decreases the intensity of the collapse. © 2018
A new method in well test interpretation using temperature transient analysis for gas wells
, Article International Petroleum Technology Conference 2007, IPTC 2007, Dubai, 4 December 2007 through 6 December 2007 ; Volume 2 , 2007 , Pages 1151-1160 ; 9781615673360 (ISBN) ; Siavoshi, J ; Sharif University of Technology
Society of Petroleum Engineers
2007
Abstract
Interpretation of temperature logs has been done successfully in wells to identify water or gas entries location, detect casing leaks, and evaluate cement placement. This paper shows how knowledge of the Joule-Thomson cooling effect and frictional heating effect can be applied for well test interpretation. Many analysts rely on pressure derivative curve to diagnose wellbore storage period and radial flow regime on pressure transient data. However, there are field examples that flow regimes can't be accurately determined. During transient tests, both pressure and temperature are changed depending on downhole flow rate. In gas producing wells, Joule-Thomson cooling and frictional heating...
Experimental and modelling investigations of asphaltene precipitation during pressure depletion and gas injection operations
, Article Petroleum Science and Technology ; Vol. 32, issue. 15 , August , 2014 , pp. 1868-1875 ; ISSN: 10916466 ; Alizadeh, A ; Afshari, S ; Kharrat, R ; Ghazanfari, M ; Sharif University of Technology
Abstract
Asphaltene precipitation problems manifest themselves in different stages of oil reservoirs production. Experimental and modeling investigations are, therefore, employed as promising tools to assist in predictions of asphaltene precipitation problems and selection of proper production facilities. This study concerns experimental and modeling investigations of asphaltene precipitation during natural production and gas injection operations for a heavy Iranian crude oil at reservoir conditions. First, with design and performance of high pressure-high temperature experiments, asphaltene precipitation behavior is comprehensively investigated; the effects of pressure and temperature are fully...
Modelling-based optimisation of the direct synthesis of dimethyl ether from syngas in a commercial slurry reactor
, Article Chinese Journal of Chemical Engineering ; Volume 21, Issue 6 , June , 2013 , Pages 611-621 ; 10049541 (ISSN) ; Kazemeini, M ; Fattahi, M ; Sharif University of Technology
2013
Abstract
In the present study, we developed a multi-component one-dimensional mathematical model for simulation and optimisation of a commercial catalytic slurry reactor for the direct synthesis of dimethyl ether (DME) from syngas and CO2, operating in a churn-turbulent regime. DME productivity and CO conversion were optimised by tuning operating conditions, such as superficial gas velocity, catalyst concentration, catalyst mass over molar gas flow rate (W/F), syngas composition, pressure and temperature. Reactor modelling was accomplished utilising mass balance, global kinetic models and heterogeneous hydrodynamics. In the heterogeneous flow regime, gas was distributed into two bubble phases: small...
The determination of effective diffusivity coefficients in a solvent gas heavy oil system for methane
, Article Petroleum Science and Technology ; Volume 30, Issue 24 , 2012 , Pages 2582-2593 ; 10916466 (ISSN) ; Dadvar, M ; Kharrat, R ; Ghazanfari, M. H ; Sharif University of Technology
2012
Abstract
In this investigation, an accurate high pressure and temperature diffusion setup was applied to measure the diffusion coefficients of methane in Iranian heavy oils in presence and absence of porous media by using the pressure-decay method. The solvent diffusivity in heavy oil was determined by both graphical and numerical methods. In addition, the effects of the porous medium and the temperature on the molecular diffusion coefficient of the solvent gas in the liquid phase were discussed and finally, using experimental data, a functionality dependence of molecular diffusivity on temperature and porous medium characteristics was proposed
Thermal interaction of laser beam with particulate flow in mini-channels
, Article ASME 2011 9th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM 2011, 19 June 2011 through 22 June 2011 ; Volume 2 , June , 2011 , Pages 355-366 ; 9780791844649 (ISBN) ; Saidi, M. S ; Saidi, M. H ; Shafii, M. B ; Sharif University of Technology
2011
Abstract
Optical propulsion via laser source is a relatively new and non-contact tool for manipulation of microscopic objects. The method is based on the radiation pressure of light photons on the micron sized particles. Applications of the technique mainly cover microscopic separation, purification and cellular studies. Due to high power intensity of laser beams, absorption of light may result in heating and damage of objects to be manipulated. In addition, the difference between heated and cold zones can lead to a naturally driven flow around the objects. So precisely controlled conditions should be set up to avoid thermal effects. In this work, a theoretical study is conducted to investigate the...
Modeling of asphaltene aggregation phenomena in live oil systems at high pressure-high temperature
, Article Fluid Phase Equilibria ; Volume 423 , 2016 , Pages 55-73 ; 03783812 (ISSN) ; Rashidi, F ; Mousavi Dehghani, S. A ; Ghazanfari, M. H ; Sharif University of Technology
Elsevier
Abstract
In spite of the development of different experimental methods and theoretical models devoted to understand and predict the asphaltene behavior in dead/model oils, the asphaltene aggregation phenomena in live oil systems at high pressure-high temperature conditions has been grossly missing in the available literature. In this study, a population balance model with geometric scaling approach is proposed to simulate the asphaltene aggregates growth in time for live oil systems. Appropriate collision kernels are incorporated to describe the aggregation mechanisms taking into account the effect of pressure, temperature and oil characteristics. In modeling of the asphaltene aggregation phenomena...
Fractal analysis of asphaltene aggregation phenomena in live oils at elevated pressure and temperature
, Article Particulate Science and Technology ; 2016 , Pages 1-9 ; 02726351 (ISSN) ; Rashidi, F ; Mousavi Dehghani, S. A ; Ghazanfari, M. H ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
In this work, high-pressure microscopy technique was used to measure the size and fractal dimension of asphaltene aggregates formed in different live oil samples at elevated pressures and temperatures. It was found that the asphaltene aggregates in live oil samples are irregular fractal-like structures with pressure−temperature-dependent fractal dimensions. By monitoring the variation of the fractal dimension and size of the asphaltene aggregates with pressure and temperature, the mechanisms responsible for asphaltene aggregation process at elevated pressures and temperatures can be well predicted. The range of fractal dimension of asphaltene aggregates in live oils is similar to that...
Evaluation of effect of temperature and pressure on the dynamic interfacial tension of crude oil/aqueous solutions containing chloride anion through experimental and modelling approaches
, Article Canadian Journal of Chemical Engineering ; 2017 ; 00084034 (ISSN) ; Ayatollahi, S ; Sharif University of Technology
Wiley-Liss Inc
2017
Abstract
The interfacial properties of crude oil are highly complex and are not yet well understood. This study aimed to evaluate the effect of temperature (30-80°C) and pressure (3.44-27.58MPa) on the dynamic interfacial tension (IFT) of crude oil/aqueous solutions consisting of 15000ppm of salt containing different chloride anions, e.g. NaCl, KCl, MgCl2, and CaCl2. To reach this goal, several parameters, such as dynamic and equilibrium IFT, adsorption time, diffusivity of resin, and asphaltene as surface-active agents from bulk of crude oil towards fluid/fluid interface and surface excess concentration of them at the interface, were compared as a function of temperature, pressure, and ion type. The...
A modified method for detection of interface and onset point in the asphaltenic fluids
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; 2020 ; Bayat Shahparast, M ; Barzegar, F ; Sharif University of Technology
Taylor and Francis Inc
2020
Abstract
Asphaltene precipitation and deposition causes many serious problems to the petroleum industry from the reservoir to the surface facilities. Therefore, it is important to bring it under control by finding a method to accelerate or slow down its precipitation and deposition. For achieving this purpose two parameters play an important role; onset point of the precipitation and amount of the deposited phase. When asphaltene precipitates, it is capable of depositing in the solution. After the deposition, the solution split into two phases; asphaltene-rich and asphaltene-lean. Determining the amount of the deposited phase needs to distinguish the interface between two phases. In this study, a...
Pressure and temperature functionality of paraffin-carbon dioxide interfacial tension using genetic programming and dimension analysis (GPDA) method
, Article Journal of Natural Gas Science and Engineering ; Volume 20 , September , 2014 , Pages 407-413 ; ISSN: 18755100 ; Jahromi, I. R ; Zolghadr, A ; Ayatollahi, S ; Sharif University of Technology
Abstract
A precise semi-empirical correlation for the calculation of interfacial tension (IFT) between the carbon dioxide and paraffin group to be used in an enhanced oil recovery process and the chemical industry is introduced. Genetic programming and dimension analysis (GPDA) are combined to create a correlation for the calculation of the equilibrium interfacial tension of the carbon dioxide and paraffin group, based on the explicit functionality of the pressure and temperature. The parameters of the correlation consist of critical temperature, critical pressure, density of paraffin at normal temperature, and diffusion coefficients. The pool of experimental data for developing the correlation...
Prediction of sour gas compressibility factor using an intelligent approach
, Article Fuel Processing Technology ; Volume 116 , 2013 , Pages 209-216 ; 03783820 (ISSN) ; Hemmati Sarapardeh, A ; Mirabbasi, S. M ; Nikookar, M ; Mohammadi, A. H ; Sharif University of Technology
2013
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...
Plasma core at the center of a sonoluminescing bubble
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 87, Issue 1 , 2013 ; 15393755 (ISSN) ; Sadighi Bonabi, R ; Sharif University of Technology
2013
Abstract
Considering high temperature and pressure during single bubble sonoluminescence collapse, a hot plasma core is generated at the center of the bubble. In this paper a statistical mechanics approach is used to calculate the core pressure and temperature. A hydrochemical model alongside a plasma core is used to study the bubble dynamics in two host liquids of water and sulfuric acid 85 wt % containing Ar atoms. Calculation shows that the extreme pressure and temperature in the plasma core are mainly due to the interaction of the ionized Ar atoms and electrons, which is one step forward to sonofusion. The thermal bremsstrahlung mechanism of radiation is used to analyze the emitted optical energy...
Thermo-hydro-mechanical modeling of impermeable discontinuity in saturated porous media with X-FEM technique
, Article Engineering Fracture Mechanics ; Volume 96 , December , 2012 , Pages 701-723 ; 00137944 (ISSN) ; Moallemi, S ; Haghighat, E ; Sharif University of Technology
2012
Abstract
In this paper, the extended finite element method is presented for thermo-hydro-mechanical (THM) modeling of impermeable discontinuities in saturated porous media. The X-FEM technique is applied to the THM governing equations for the spatial discretization, followed by a generalized Newmark scheme for the time domain discretization. The displacement field is enriched by the Heaviside and crack tip asymptotic functions, and the pressure and temperature fields are enriched by the Heaviside and appropriate asymptotic functions. The process is accomplished by partitioning the domain with triangular sub-elements. Numerical examples are presented to demonstrate the capability of proposed technique...
Investigation of asphaltene precipitation in miscible gas injection processes: Experimental study and modeling
, Article Brazilian Journal of Chemical Engineering ; Volume 29, Issue 3 , 2012 , Pages 665-676 ; 01046632 (ISSN) ; Dabiri, M ; Dabir, B ; Rashtchian, D ; Emadi, M. A ; Sharif University of Technology
2012
Abstract
Asphaltene precipitation during natural depletion and miscible gas injection is a common problem in oilfields throughout the world. In this work, static precipitation tests are conducted to investigate the effects of pressure, temperature and gas type and concentration on asphaltene instability. Three different oil samples have been studied under reservoir conditions with/without nitrogen and methane injection. Besides applying common thermodynamic models, a new scaling equation is presented to predict asphaltene precipitation under HPHT gas injection. Extensive published data from the literature are also used in model development. The scaling approach is attractive because it is simple and...
Comprehensive study of asphaltene precipitation due to gas injection: Experimental investigation and modeling
, Article Society of Petroleum Engineers - SPE Enhanced Oil Recovery Conference 2011, EORC 2011, 19 July 2011 through 21 July 2011 ; Volume 1 , July , 2011 , Pages 208-219 ; 9781618390929 (ISBN) ; Moradi, S ; Dabir, B ; Emadi, M. A ; Rashtchian, D ; Sharif University of Technology
2011
Abstract
Asphaltene precipitation during natural depletion and miscible gas injection is a common problem in oilfields throughout the world. In this work, static precipitation tests are conducted to investigate effect of pressure, temperature and gas type and concentration on asphaltene instability. Three different oil samples are studied under reservoir conditions with/without nitrogen and methane injection. Besides applying common thermodynamic models, a new scaling equation is presented to predict asphaltene precipitation under HPHT gas injection. Published data from literature are also used in model development. The scaling approach is attractive because it is simple and complex asphaltene...