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asphaltene-deposition
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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...
A core scale investigation of Asphaltene precipitation during simultaneous injection of oil and CO2: An experimental and simulation study
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Vol. 36, issue. 10 , Dec , 2014 , pp. 1077-1092 ; ISSN: 15567036 ; Rashtchian, D ; Ghazanfari, M. H ; Kharrat, R ; Sharif University of Technology
Abstract
Although CO2 injection significantly increases the amount of oil recovered, it can cause asphaltene deposition in oil reservoirs. Asphaltene deposition leads to formation damage, in which treatment is a costly and problematic operation. In this work, impact of asphaltene precipitation and deposition during CO2 injection are investigated for recombined oil both in sandstone and carbonate core samples through dynamic flow experiments. Injection of oil and CO2 was performed simultaneously. Then, pressure drops along the core were recorded continuously to estimate permeability reductions during the experiments. Online viscosity of injected fluid was measured by a designed capillary viscometer....
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...
SAFT model for upstream asphaltene applications
, Article Fluid Phase Equilibria ; Volume 359 , December , 2013 , Pages 2-16 ; 03783812 (ISSN) ; Tavakkoli, M ; Vargas, F. M ; Gonzalez, D. L ; Chapman, W. G ; Sharif University of Technology
2013
Abstract
The increasing incidence of flow assurance problems caused by asphaltene deposition during oil production has motivated the development of numerous theoretical models and experimental methods to analyze this complex phenomenon. Even more challenging are the prediction of the occurrence and the magnitude of asphaltene deposition. It is well accepted that precipitation of asphaltene is a necessary condition for deposition. Hence, a significant amount of work has been devoted to the understanding of the conditions at which asphaltene precipitate from the crude oil. Although, several models seem to work well for correlating available data of onsets of asphaltene precipitation, they usually lack...
Assessment of asphaltene deposition due to titration technique
, Article Fluid Phase Equilibria ; Volume 339 , 2013 , Pages 72-80 ; 03783812 (ISSN) ; Amani, M ; Kiani, M. A ; Chamkalani, R ; Sharif University of Technology
2013
Abstract
Due to problems followed by asphaltene deposition, which cause many remedial processes and costs, it seemed necessary to develop equations for determining asphaltene precipitation quantitatively or qualitatively. In this study a new scaling equation as a function of temperature, molecular weight, and dilution ratio (solvent) has been developed. This equation can be used to determine the weight percent of precipitated asphaltene in the presence of different precipitants (solvents). The proposed methodology utilizes least square support vector machines/regression (LSSVM/LSSVR) to perform nonlinear modeling. This paper proposes a new feature selection mechanism based on coupled simulated...
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...
Quantitative analysis of ultrasonic wave radiation on reversibility and kinetics of asphaltene flocculation
, Article 4th International Conference and Exhibition: New Discoveries through Integration of Geosciences, Saint Petersburg, 5 April 2010 through 8 April 2010 ; 2010 ; Najafi, I ; Ghazanfari, M. H ; Kharrat, R ; Ghotbi, C ; Sharif University of Technology
European Association of Geoscientists and Engineers, EAGE
2010
Abstract
Recently, it was found that ultrasonic wave technology can be used as a method for asphaltene deposits removal from the near wellbore region. However, ultrasounds can affect asphaltene resolution.In this work, asphaltene resolution in several crude oil samples exposed to ultrasonic waves for different time intervals is studied by confocal microscopy. The colloidal structure of flocks is described by analysis of asphaltene particle size distribution to investigate ultrasonic application in solving asphaltene deposition problems.. The results show that for the first 90 minutes of flocculation time, the size of aggregates increases rapidly, and reaction limited aggregation model matches well...
New two-dimensional particle-scale model to simulate asphaltene deposition in wellbores and pipelines
, Article Energy and Fuels ; Volume 32, Issue 3 , 2018 , Pages 2661-2672 ; 08870624 (ISSN) ; Joonaki, E ; Taghikhani, V ; Bozorgmehry Boozarjomehry, R ; Chapoy, A ; Tohidi, B ; Sharif University of Technology
American Chemical Society
2018
Abstract
A new two-dimensional dynamic model was developed to simulate asphaltene precipitation, aggregation, and deposition at isothermal and non-isothermal conditions. The perturbed-chain statistical associating fluid theory equation of state was used to model the asphaltene precipitation. Also, novel kinetic models were used to account for the aggregation and deposition of asphaltene particles. The effect of the aggregate size on the rate of aggregation and deposition was studied, and it was concluded that the rate of asphaltene deposition increases, while the concentration of nanoaggregates increases in the well column. The tendency of smaller aggregates to deposit on the surface could be...
Evaluation of PC-SAFT model and support vector regression (SVR) approach in prediction of asphaltene precipitation using the titration data
, Article Fluid Phase Equilibria ; Volume 456 , 2018 , Pages 171-183 ; 03783812 (ISSN) ; Ghotbi, C ; Jafari Behbahani, T ; Sharifi, K ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Asphaltene deposition in porous media, wellbore and surface facilities has been a severe problem in petroleum industry which causes considerable remediation costs annually. Asphaltenes are heavy and polydisperse fractions of crude oil which are insoluble in n-alkanes such as n-heptane. In this work, three Iranian crude oils were prepared for titration experiments with n-pentane, n-heptane and n-dodecane at different solvent ratios and constant temperature. The experimental data were correlated by perturbed chain form of statistical associating fluid theory (PC-SAFT). The association of asphaltene molecules has been considered in this model with adjusting the uncertain parameters (such as...
Simulation of Asphaltene Slurry Flow for Oil Dominant Systems in Vertical Wells
,
Ph.D. Dissertation
Sharif University of Technology
;
Taghikhani, Vahid
(Supervisor)
;
Pishvaie, Mahmoud Reza
(Supervisor)
;
Masihi, Mohsen
(Co-Advisor)
;
Chapman, Walter
(Co-Advisor)
;
Panuganti, Sai
(Co-Advisor)
Abstract
In the upstream asphaltene flow assurance community, both academics and industries are actively involved to predict the asphaltene deposit profile in wellbores and pipelines. The main objective of this study is to contribute to the thermodynamic and transport modeling of asphaltene in order to predict its precipitation, aggregation and deposition. For a better knowledge of the flow properties of asphaltene containing crude oils, it is necessary to understand how asphaltene affect the rheological properties. In this work, the information on such rheological properties of oil-asphaltene slurry systems is provided. The results of rheological experiments for two Iranian crude oils show that the...
An experimental investigation of permeability impairment under dynamic flow conditions due to natural depletion in an Iranian oilfield
, Article Petroleum Science and Technology ; Volume 31, Issue 3 , 2013 , Pages 250-261 ; 10916466 (ISSN) ; Bagherzadeh, H ; Bolouri, H ; Sharif University of Technology
2013
Abstract
Asphaltene deposition is an issue that has received much attention since it has been shown to be the cause of major production problems. It leads to permeability reduction under the processes of natural depletion as well as hydrocarbon gas/CO2 injection. Though a great deal of researches have focused on studying permeability impairment in reservoir rocks, little is known about the asphaltene deposition mechanisms that control the permeability reduction for Iranian reservoirs. In this work, an experimental effort is made to investigate the permeability impairment of core samples of Iranian oil reservoirs. The experiments are performed on both sandstone and carbonate rock types at reservoir...
Multivariate curve resolution alternating least-squares as a tool for analyzing crude oil extracted asphaltene samples
, Article Energy and Fuels ; Volume 26, Issue 9 , 2012 , Pages 5663-5671 ; 08870624 (ISSN) ; Hemmateenejad, B ; Sedghamiz, T ; Khosousi, T ; Ayatollahi, S ; Seiedi, O ; Sayyad Amin, J ; Sharif University of Technology
ACS
2012
Abstract
Asphaltene deposition in the early stage of the oil reservoir life and later during any stimulation process emerges critical problems to the petroleum industry. Deposition of asphaltene aggregates raises strict problems in industries and demands markedly a practical and scientific knowledge of the mechanisms of aggregation and precipitation. Fluorescence emission spectroscopy has been widely used to illuminate the fundamental properties of crude oils and asphaltenes. It proposes analysis of some details of equilibrium, dynamic behavior, and aggregation composition of crude oil under specific condition. In this work, the fluorescence spectra of crude-oil extracted asphaltene samples were...
Optimization assisted asphaltene deposition modeling in porous media during a natural depletion scheme
, Article Petroleum Science and Technology ; Volume 30, Issue 9 , Mar , 2012 , Pages 958-965 ; 10916466 (ISSN) ; Bagheri, M ; Kharrat, R ; Ghazanfari, M ; Ghotbi, C ; Sharif University of Technology
2012
Abstract
Changes in thermodynamic properties such as pressure, temperature, and composition may result in asphaltene precipitation and deposition in porous media. In addition, asphaltene deposition can cause wettability alteration, permeability reduction, and ultimately a decrease in the productivity of a reservoir. Natural depletion is one of the most common processes of asphaltene deposition in which pressure changes destabilize the dissolved asphaltene in the oil and settle them onto the rock surface. In this work, natural depletion experiments in consolidated core samples were performed under simulated reservoir conditions to obtain reliable data and analyze the asphaltene deposition mechanisms....
Asphaltene deposition during CO 2 injection and pressure depletion: A visual study
, Article Energy and Fuels ; Volume 26, Issue 2 , December , 2012 , Pages 1412-1419 ; 08870624 (ISSN) ; Ayatollahi, S ; Alamdari, A ; Zolghadr, A ; Dashti, H ; Kord, S ; Sharif University of Technology
Abstract
Carbon dioxide miscible flooding has become a popular method for Enhanced Oil Recovery (EOR) because it not only efficiently enhances oil recovery but also considerably reduces green house gas emissions. However, it can significantly cause asphaltene deposition, which leads to serious production problems such as wettability alteration, plugging of the reservoir formation, blocking the transportation pipelines, etc. It is crucial to investigate the effects of different factors on asphaltene deposition. A novel experimental setup was prepared to employ a high-pressure visual cell for investigation of asphaltene deposition on a model rock under typical reservoir conditions. The evolution of...
Permeability impairment study due to asphaltene deposition: experimental and modeling approach
, Article Transport in Porous Media ; Volume 91, Issue 3 , February , 2012 , Pages 999-1012 ; 01693913 (ISSN) ; Ghoodjani, E ; Sharif University of Technology
2012
Abstract
This fact is well known that during any scenario of production, asphaltene deposition in porous media has a substantial effect on oil flow. But a clear understanding of asphaltene deposition mechanisms can help to minimize asphaltenic problem in oil-bearing formations. In this study, the experimental results of three dynamic CO 2 miscible injection tests were investigated. Regarding the effects of adsorption, mechanical entrapment, and sweeping mechanisms on permeability behavior, a mathematical mass and permeability variation model were developed. According to the experimental results asphaltene deposition causes a 70% loss of sand stone initial permeability while the loss is significantly...
Investigation of asphaltene deposition mechanisms during primary depletion and CO2 injection
, Article Society of Petroleum Engineers - 9th European Formation Damage Conference 2011, 7 June 2011 through 10 June 2011 ; Volume 1 , June , 2011 , Pages 223-231 ; 9781617829673 (ISBN) ; Ghotbi, C ; Taghikhani, V ; Shahrabadi, A ; Sharif University of Technology
2011
Abstract
Asphaltene deposition causes serious problems in the oil industry. Variation of oil composition and reservoir pressure is reported to be the most important factors that influence asphaltene deposition from reservoir oil. In this study, a mathematical model was developed to simulate asphaltene deposition during primary depletion and CO2 injection. The main purpose of this study is to investigate and to compare asphaltene deposition mechanisms due to primary depletion and CO2 injection. The solid model as thermodynamic model was applied to investigate asphaltene precipitation. A numerical model was established to the governing equations both in space and time and model parameters were...
Experimental investigation of the asphaltene deposition process during different production schemes
, Article Oil and Gas Science and Technology ; Volume 66, Issue 3 , 2011 , Pages 507-519 ; 12944475 (ISSN) ; Kharrat, R ; Ghotby, C ; Sharif University of Technology
2011
Abstract
Experimental Investigation of the Asphaltene Deposition Process during Different Production Schemes - This paper presents the results of asphaltene precipitation and deposition during lean gas injection, CO2 injection and natural depletion in reservoir conditions. In addition, the effect of variations in operating pressure, injection gas concentration and production rate on asphaltene precipitation and deposition were investigated. The severity of asphaltene deposition was found to be more pronounced in lean gas injection in comparison with CO2 injection and natural depletion. Increasing the flow rate in natural depletion xperiments showed a considerable increase in asphaltene deposition,...
Experimental study and mathematical modeling of asphaltene deposition mechanism in core samples
, Article Oil and Gas Science and Technology ; Volume 70, Issue 6 , Nov , 2015 , Pages 1051-1074 ; 12944475 (ISSN) ; Ghotbi, C ; Taghikhani, V ; Shahrabadi, A ; Sharif University of Technology
Editions Technip
2015
Abstract
In this work, experimental studies were conducted to determine the effect of asphaltene deposition on the permeability reduction and porosity reduction of carbonate, sandstone and dolomite rock samples using an Iranian bottom hole live oil sample which is close to reservoir conditions, whereas in the majority of previous work, a mixture of recombined oil (a mixture of dead oil and associated gas) was injected into a core sample which is far from reservoir conditions. The effect of the oil injection rate on asphaltene deposition and permeability reduction was studied. The experimental results showed that an increase in the oil injection flow rate can result in an increase in asphaltene...