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asphaltenes
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Modeling of Asphaltene Deposition in Flow Lines Considering Pressure and Temperature Drop
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahabeddin (Supervisor) ; Assareh, Mehdi (Supervisor)
Abstract
Crude oil is made up of dozens of chemicals which based on their structural similarity, SARA test separate it into four categories: saturates, aromatics, resins and asphaltene. Asphaltenes are recognized as the largest, heaviest and the most polarizable fraction of the crude oil which are in thermodynamic equilibrium with oil at reservoir conditions. Each of the physical, chemical, electrical or mechanical disruption of this balance during production can result in instability and asphaltene precipitation may occur and eventually led to deposition in the reservoir, wells, pipelines, etc. Due to the fact that most changes in temperature and pressure will generated in the wells, thus...
Dynamic Modeling and Experimental Study of Asphaltene Deposition in Wellbore Considering Mechanism of Precipitation, Aggregation and Deposition
,
Ph.D. Dissertation
Sharif University of Technology
;
Ghotbi, Cyrus
(Supervisor)
;
Dabir, Bahram
(Co-Supervisor)
;
Taghikhani, Vahid
(Co-Supervisor)
Abstract
Efforts to identify, predict, and resolve problems linked to asphaltenes and flow assurance have resulted in the development of numerous laboratory and modelling techniques. However, there has been little research on the molecular structure of asphaltenes and how it relates to solubility, stability, aggregation, and deposition behavior. Not only was a thorough structural analysis of asphaltene extracted from three samples of light, medium, and heavy oil performed in this study, but medium oil asphaltene was also fractionated into three sub-fractions based on solubility, with minimum, medium, and maximum solubility, and each subfraction was subjected to a structural analysis. All asphaltene...
Experimental determination of interfacial tension and miscibility of the CO2-crude oil system; Temperature, pressure, and composition effects
, Article Journal of Chemical and Engineering Data ; Vol. 59, issue. 1 , December , 2014 , p. 61-69 ; ISSN: 00219568 ; Ayatollahi, S ; Ghazanfari, M. H ; Masihi, M ; Sharif University of Technology
Abstract
Interfacial tension (IFT) as one of the main properties for efficient CO2 flooding planning in oil reservoirs depends strongly on pressure, temperature, and composition of the reservoir fluids. Therefore, it is important to measure this property at real reservoir conditions for successful field development plan. In this study, an axisymmetric drop shape analysis (ADSA) has been utilized to measure the equilibrium IFTs between crude oil and CO2 at different temperatures and pressures. Moreover, minimum miscibility pressures (MMP) and first-contact miscibility pressures (P max) of crude oil/CO2 systems at different temperatures are determined by applying the vanishing interfacial tension (VIT)...
Investigation of asphaltene adsorption in sandstone core sample during CO2 injection: Experimental and modified modeling
, Article Fuel ; Vol. 133 , 2014 , Pages 63-72 ; ISSN: 00162361 ; Ghotbi, C ; Taghikhani, V ; Shahrabadi, A ; Sharif University of Technology
Abstract
In this work, asphaltene adsorption in a sandstone core sample under dynamic conditions and during miscible CO2 injection was studied using live oil sample which is close to real conditions in petroleum reservoirs. In order to investigate of damage in sandstone core sample by the deposited material such as asphaltene, the morphology analysis of sandstone core sample using scanning electron microscopic method was studied. Also analyses of the adsorbed material in sandstone core sample by Soxhlet extraction using an azeotrope mixture and with SARA method were performed. The experimental results show that by increasing the flow rate of injected CO2, the amount of asphaltene in retained material...
Effects of paraffinic group on interfacial tension behavior of CO 2-asphaltenic crude oil systems
, Article Journal of Chemical and Engineering Data ; Vol. 59, issue. 8 , 2014 , Pages 2563-2569 ; ISSN: 00219568 ; Zebarjad, F. S ; Taghikhani, V ; Ayatollahi, S ; Sharif University of Technology
Abstract
The interfacial tension (IFT) of a crude oil/CO2 system is recognized as the main property affecting the efficiency of CO2 flooding during an enhanced oil recovery (EOR) process. The addition of a paraffin group hydrocarbon to asphaltenic crude oils as an asphaltene precipitant component is aimed to mimic the asphaltene precipitation process during crude oil production and transportation. Asphaltene precipitation would critically affect the interfacial behavior of crude oil/CO2 systems. In the first part of this study, the equilibrium densities of oil samples which contain n-heptane at different ratios were measured over varying pressures at 323 K. Then, the equilibrium IFT between CO2 and...
Effect of resins on asphaltene deposition and the changes of surface properties at different pressures: A microstructure study
, Article Energy and Fuels ; Vol. 28, issue. 4 , April , 2014 , pp. 2415-2421 ; ISSN: 08870624 ; Zolghadr, A ; Ayatollahi, S ; Sharif University of Technology
Abstract
Asphaltene deposition has hindered oil production from asphaltenic oil reservoirs through deposition in reservoir rock and surface facilities. This paper investigates the effect of resin on asphaltene deposition at different pressures. To investigate the asphaltene deposition in the presence of resins at reservoir temperature and different pressures, a pressure, volume, and temperature (PVT) visual cell was designed. A high-resolution microscope and image processing software were used to detect and determine the amount of deposited asphaltene as well as its size distribution at different conditions. Two types of Iranian crude oils with different potential of deposition (low and high) were...
Asphaltene precipitation due to natural depletion of reservoir: Determination using a SARA fraction based intelligent model
, Article Fluid Phase Equilibria ; Volume 354 , September , 2013 , Pages 177-184 ; 03783812 (ISSN) ; Alipour Yeganeh Marand, R ; Naseri, A ; Safiabadi, A ; Gharagheizi, F ; Ilani Kashkouli, P ; Mohammadi, A. H ; Sharif University of Technology
2013
Abstract
Precipitation of asphaltene leads to rigorous problems in petroleum industry such as: wettability alterations, relative permeability reduction, blockage of the flow with additional pressure drop in wellbore tubing, upstream process facilities and surface pipelines. Experimentally determination of the asphaltene precipitation is costly and time consuming. Therefore, searching for some other quick and accurate methods for determination of the asphaltene precipitation is inevitable. The objective of this communication is to present a reliable and predictive model namely, the least - squares support vector machine (LSSVM) to predict the asphaltene precipitation. This model has been developed and...
Asphaltene deposition in carbonate rocks: Experimental investigation and numerical simulation
, Article Energy and Fuels ; Volume 26, Issue 10 , June , 2012 , Pages 6186-6199 ; 08870624 (ISSN) ; Miri, R ; Ayatollahi, S ; Escrochi, M ; Sharif University of Technology
2012
Abstract
Oil production from asphaltenic oil reservoirs has always encountered difficulties, such as plugging and unpredictable fluid properties. To physically recognize the aspects of asphaltene deposition, several dynamic and static asphaltene deposition tests were designed and performed on one of the giant south Iranian oil reservoirs using dead and live crude oil and real core samples. Moreover, the effects of fluid velocity on the extent of damage were investigated. It was found that surface deposition of asphaltene particles is the main source of formation damages in the porous media and the resulting permeability impairment obeys an exponential behavior. All of the experiments confirm that...
Modeling formation damage due to asphaltene deposition in the porous media
, Article Energy and Fuels ; Volume 25, Issue 2 , February , 2011 , Pages 753-761 ; 08870624 (ISSN) ; Tohidi, B ; Jamialahmadi, M ; Rashtchian, D ; Sharif University of Technology
2011
Abstract
Asphaltene deposition in a reservoir severely reduces the effective permeability and results in a reduction in oil production. The main term in asphaltene deposition modeling in the porous media is pore surface deposition. Previous models do not describe the effects of different parameters (i.e., concentration, velocity, and temperature) on the pore surface deposition term. We report the results of a series of experiments carried out to study the effects of the above parameters on the surface deposition term using an accurate thermal method. Based on these data, a new expression for the surface deposition term has been developed and implemented in asphaltene deposition modeling. The...
Effects of native and non-native resins on asphaltene deposition and the change of surface topography at different pressures: an experimental investigation
, Article Energy and Fuels ; Volume 29, Issue 9 , July , 2015 , Pages 5487-5494 ; 08870624 (ISSN) ; Zolghadr, A ; Ayatollahi, S ; Sharif University of Technology
American Chemical Society
2015
Abstract
Asphaltene deposition during oil production and transportation causes extensive damage to reservoirs and wellhead equipment. In this study, the effects of native and non-native resins as well as those of their mixtures on the asphaltene deposition process are investigated. A novel pressure, volume, and temperature (PVT) visual cell is used to check the effect of resin on asphaltene deposition at different pressures and reservoir temperatures. Two Iranian crude oil samples with different potentials of asphaltene deposition (low and high) were used in these tests. During depressurizing in the presence of native and non-native resins, the amount of asphaltene deposited was measured. To monitor...
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...
A novel method to develop a new scaling equation for modeling of asphaltene precipitation
, Article Society of Petroleum Engineers - SPE/EAGE Reservoir Characterization and Simulation Conference 2009 - Overcoming Modeling Challenges to Optimize Recovery, 19 October 2009 through 21 October 2009 ; Volume 2 , 2009 , Pages 831-844 ; 9781615677443 (ISBN) ; Kharrat, R ; Mirzabozorg, A ; Ghotbi, C ; Dastkhan, Z ; Sharif University of Technology
Abstract
Most investigations showed that the prevalent thermodynamic models are incapable of predicting asphaltene precipitation without extensive data fitting. This is primarily due to lack of knowledge of the asphaltene properties, its complex nature and the large number of parameters affecting precipitation. Hece, several authors tried to generate a simple and universe mathematical model in order to predict the amount of asphaltene precipitation. In spite of these efforts, the authors only considered temperature and type of solvents as the effective parameters in generating their scaling equations. The major disadvantage of these models is their inability in predicting the amount of asphaltene...
Effect of ultrasonic irradiation treatment on rheological behaviour of extra heavy crude oil: A solution method for transportation improvement
, Article Canadian Journal of Chemical Engineering ; Volume 95, Issue 1 , 2017 , Pages 83-91 ; 00084034 (ISSN) ; Ramazani S. A, A ; Alijani Alijanvand, H ; Ghazanfari, M. H ; Ghanavati, M ; Sharif University of Technology
Wiley-Liss Inc
2017
Abstract
The highly viscous property of heavy oil often causes problems in its transportation in pipelines. Mixing heavy oil with light oil as well as ultrasound treatment are viable solutions to this problem. In this study, extra heavy crude oil samples were first diluted with 0, 0.05, 0.1, and 0.15 mL/mL (0, 5, 10, and 15 vol%) of a light crude oil; then the mixture was irradiated by ultrasonic waves for 0, 5, 10, 15, and 20 min; finally the viscous shear functions of all mixtures was measured at different values of shear rate at different temperature levels. The results revealed that the minimum viscosity of the diluted extra heavy crude oil samples was obtained at 10 min of ultrasonic...
Experimental investigation of asphaltene content effect on crude oil/co2 minimum miscibility pressure
, Article Periodica Polytechnica Chemical Engineering ; Volume 64, Issue 4 , 2020 , Pages 479-490 ; Gandomkar, A ; Montazeri, G ; Honarvar, B ; Azdarpour, A ; Rezaee, M ; Sharif University of Technology
Budapest University of Technology and Economics
2020
Abstract
Minimum Miscibility Pressure (MMP) is regarded as one of the foremost parameters required to be measured in a CO2 injection process. Therefore, a reasonable approximation of the MMP can be useful for better development of injection conditions as well as planning surface facilities. In this study, the impact of asphaltene content ranging from 3.84 % to 16 % on CO2/heavy oil MMP is evaluated. In this respect, slim tube miscibility and Vanishing Interfacial Tension (VIT) tests are used. Regarding the VIT test, the Interfacial Tension (IFT) is measured by means of two methods including pendant drop and capillary apparatuses, and thereafter the MMP measurement error between slim tube and VIT...
Effect of salts and their interaction with ingenious surfactants on the interfacial tension of crude oil/ionic solution
, Article Chinese Journal of Chemical Engineering ; Volume 28, Issue 1 , January , 2020 , Pages 224-235 ; Parvizi, R ; Ayatollahi, S ; Ghaseminejad Raeeni, E ; Sharif University of Technology
Chemical Industry Press
2020
Abstract
Understanding the roles of asphaltene and resin as natural surfactants existed in crude oil can enlighten contradicting reported results regarding interfacial tension (IFT) of crude oil/aqueous solution as a function of salinity and ion type. In this way, this study is aimed to investigate the effect of these natural surface active agents on IFT of with special focus on SO42− anion and Mg2+ cation. Two different synthetic oil solutions of 8 wt% of the extracted asphaltene and resin dissolved in toluene are prepared, and then IFT values are measured. After that, the obtained results are compared with the IFT of intact crude oil in contact with the same saline solutions examined in the...
Experimental and Modeling Investigation of the Near Wellbore Asphaltene Deposition Damage Removal by Ultrasonic Waves
, M.Sc. Thesis Sharif University of Technology ; Ghotbi, Cyrus (Supervisor) ; Ghazanfari, Mohammad Hossein (Co-Advisor)
Abstract
This work concerns with experimental and modeling investigation of the asphaltene damage removal using ultrasonic wave irradiation. A specific core holder apparatus was designed and utilized for in situ ultrasonic exposure to damaged core plug at different conditions of exposure time, ultrasound power and distances between sound source and plug. Injection of many pore volumes of an asphaltenic crude oil was used for creating asphaltene induced damaged in porous media through permeability measurements. The deposited asphaltene during oil injection as well as asphaltene removal due to ultrasonic exposure was evaluated using IP-143 analysis. The results revealed that ultrasound application...
Stimulating Asphaltenic Oil Reservoirs, Experimental Investigation of Asphaltenic Sludge Formation to Plan Its Prevention
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahaboddin (Supervisor) ; Shad, Saeed (Supervisor)
Abstract
Formation damage is probable to occur while drilling, work-over operations, and well completion in near wellbore zone due to different reasons; which leads to excess pressure drop through this area. Well stimulation operations are proposed to remove these damages and improve oil production; among which, acidizing is known as a traditional applicable method to stimulate oil and gas wells. Although this approach is accepted and chosen as a well stimulation method to remove formation damages, its poor design and implementation results in new formation damages. One of these arises when acid contacts asphaltic oil, which causes asphaltene particle instability and asphaltic sludge rapid...
Investigation of Surfactin Behavior at the Presence of Wate, Oil, and Asphaltene
, M.Sc. Thesis Sharif University of Technology ; Roosta Azad, Reza (Supervisor) ; Yaghmaee, Soheyla (Supervisor)
Abstract
In this research, the behavior of surfactin at the presence of water, decane, and asphaltene is investigated. Decane is chosen instead of crude oil to simplify the model. In the first chapter, basic molecular structures are introduced. Furthermore, in the second chapter molecular dynamics simulation, as the main tool in these simulations, is introduced. In the third chapter, one of the most important quantities in chemical engineering, diffusion coefficient, is chosen to investigate the efficiency and accuracy of molecular dynamics simulation method to calculate such a quantity and results show that molecular dynamics simulation can present accurate quantities, more accurate than common...
Investigation the Minimum Miscibility Pressure for Crude oil with Different Asphaltene Content using Vanishing Interfacial Tension Method
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahab (Supervisor) ; Masihi, Mohsen (Supervisor) ; Ghazanfari, Mohammad Hossein (Supervisor)
Abstract
Interfacial Tension (IFT) as a main parameter for gas flooding efficiency in oil reservoirs depends highly on pressure, temperature, and composition of the reservoir fluids. Therefore, it is important to measure this parameter at real reservoir condition for successful field development plan. In this study, an axisymmetric drop shape analysis (ADSA) has been utilized to measure the equilibrium IFTs in crude oil-CO2 as well as crude oil-N2 systems at different temperatures and pressures. Moreover, minimum miscibility pressures (MMP) and first-contact miscibility pressures (Pmax) of crude oil/CO2 and crude oil/N2 systems at different temperature levels are determined by applying vanishing...
Investigating Asphaltene Biodegradability by Microorganism Considering Oil-Water Interface
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahab (Supervisor) ; Taghikhani, Vahid (Supervisor)
Abstract
Asphaltine particle precipitation may lead to serious problems in petroleum industry; including wellbore transmissibility reduction. One of the proposed remedial methods is to make a use of the microorganisms which are able to consume the heavy hydrocarbon chains.
Hydrophobicity of a cell surface is one of the parameters which greatly affect the microorganism adhesion to water insoluble hydrocarbons, in which results a higher hydrocarbon biodegradation. Consequently as the hydrophobicity of a cell surface increases; the microorganism tendency to bond with the hydrocarbon molecule enhances. The presence of a surface active agent, as an instance a chemical surfactant, will affect the...
Hydrophobicity of a cell surface is one of the parameters which greatly affect the microorganism adhesion to water insoluble hydrocarbons, in which results a higher hydrocarbon biodegradation. Consequently as the hydrophobicity of a cell surface increases; the microorganism tendency to bond with the hydrocarbon molecule enhances. The presence of a surface active agent, as an instance a chemical surfactant, will affect the...