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asphaltene-precipitation
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Total 71 records
Asphaltene Onset Prediction Using CEOS
, M.Sc. Thesis Sharif University of Technology ; Ghotbi, Cyrous (Supervisor) ; Jafari Behbahani, Taraneh (Supervisor)
Abstract
One of the main problems associated with the oil production is asphaltene precipitate in the reservoirs. In order to plan for the EOR methods, production scenario, and selection of completion technology, it is necessary to study the initiation of asphaltene precipitation called onset. Since the experimental methods is not only is so expensive and time consuming, the required materials are not available. Consequently, modeling approaches as new methods are proper substitutes for laboratory procedure. These methods need less costs and time and higher accuracy compared to the experimental investigations which are the advantages of these methods. Computational operations for onset determination...
Experimental and Simulation Study of Formation Damage Due to Asphaltene Precipitation under CO2 Injection Condition in One of Iranian Carbonate Oil Reservoirs
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davoud (Supervisor)
Abstract
Asphaltenedeposition is a major problem during natural depletion and EOR processes due to formation damage issues. It is necessary to reveal asphaltene deposition mechanisms and its effective parameters to prepare an acceptable prevention strategy. Therefore, different natural depletion and EOR experiments must performed on core samples. In this research, Effect of CO2 injection on asphaltene deposition phenomena has been surveyed. Two carbonate core samples and one sandstone core sample was used in experiments. The oil used in these experiments was recombinedoilfrom one of Iranian offshore oilfield.In order to estimate permeability reduction during experiment, injection of oil and CO2 was...
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...
Experimental and Simulation Study of Asphaltene Deposition in Porous Media
, M.Sc. Thesis Sharif University of Technology ; Ghotbi, sirous (Supervisor) ; Kharrat, Reyaz (Supervisor)
Abstract
Asphaltene deposition on reservoir rocks occurs during natural depletion as well as miscible injection processes. It causes reduction of effective pore space and consequent impairment of the ability of oil to flow through reservoir. Therefore, deposition of asphaltene causes significant formation damage and wellbore plugging, requiring expensive and difficult cleanup procedures. Thus it is necessary to be able to consider the onset, amount of deposition and also consequent damage of permeability and porosity reduction due to various factors. The objective of current work is to conduct experimental and simulation study of asphaltene deposition dynamics in one of the Iranian reservoirs. In...
Thermodynamic Modeling of Asphaltene Precipitation for One of Iranian Oil Reservoirs
, M.Sc. Thesis Sharif University of Technology ; Kharrat, Riyaz (Supervisor) ; Masihi, Mohsen (Supervisor)
Abstract
Thermodynamic modeling is a useful method for predicting of asphaltene precipitation due to various reasons, such as CO2 injection, mixing of different oils in oil storage and pressure changes. However, the application of solid model and thermodynamic micellization model, for prediction of asphaltene precipitation under gas injection condition, hasnot been improved. In this work, two computer codes which are based on two different asphaltene precipitation thermodynamic models, 1-Thermodynamic Micellization Model and 2- Solid Model, have been developed, and, used for predicting of asphaltene precipitation data reported in the literature as well as the experimental data obtained from high...
Screening of Thermodynamic Models in Predicting Phase Behavior of Asphaltenic Crudes Applicable in Dynamic Deposition Models
, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid (Supervisor)
Abstract
Prediction and prevention from asphaltene deposition is an essential topic in oil production systems that can enormously increase oil production costs. Many studies have been done to understand and predict the behavior of asphaltene-containing oils. Prediction and investigation of asphaltene precipitation are required to predict the asphaltene deposition problem. Changes in temperature, pressure, and composition can cause precipitation, and these changes are inevitable during production. This dissertation compares the thermodynamic models that can simulate asphaltene precipitation. Firstly, A comprehensive review was done to extract the maximum amount of experimental data from the literature...
Development of a Simulator to Simulate Multi-phase Flow with Asphaltene Precipitation in the Wellbore
, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Bozorgmehri, Ramin (Supervisor)
Abstract
Asphaltene, the heaviest and most polarizable fraction of crude oil, has a potential to precipitate, deposit and plug pipelines, causing considerable production costs. The main objective of this study is to contribute to the thermodynamic and transport modeling of asphaltene in order to predict its precipitation, segregation and deposition. Potential calculation of some thermophysical properties of asphaltene is also explored. Predicting the flow assurance issues caused by asphaltene requires the ability to model the phase behavior of asphaltene as a function of pressure, temperature and composition. It has been previously demonstrated that the Perturbed Chain form of Statistical Association...
Effect of Nitrogen Injection on Phase Behavior and Asphaltene Instability
, Ph.D. Dissertation Sharif University of Technology ; Rashtchian, Davood (Supervisor) ; Dabir, Bahram (Supervisor) ; Emadi, Mohammad Ali (Supervisor)
Abstract
Nitrogen injection is a promising enhanced oil recovery process. Asphaltene precipitation during miscible gas injection is a common problem in oilfields throughout the world. In this work, a comprehensive study is conducted on effect of gas injection on phase behavior and asphaltene instability of live oil samples. Effects of oil API, gas type and concentration, pressure and temperature are studied under natural depletion and nitrogen injection processes by means of high pressure filtration and a photographic procedure coupled with image analysis. Filtration results show that nitrogen destabilizes asphaltenes more compared to methane and the problem is more severe for heavier crude samples....
Microscopic Investigation of Asphaltene Precipitation during Water flooding Process at Laboratory Condition
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahaboddin (Supervisor) ; Ghazanfari, Mohammad Hossein (Supervisor)
Abstract
The study of low-salinity water flooding or smart water flooding as secondary or tertiary oil recovery methods started in 1960 and many researchers have studied the effect of ions types on asphaltene precipitation/deposition during the injecting water into the oil reservoirs. To reduce the asphaltene challenges, one needs to properly investigate this phenomenon and better understanding of the cause of precipitation. It is already known that the amount of asphaltene deposition can be reduced by controlling the deposition criteria. For example, water microemulsion in the oil phase would cause the asphaltenes to be adsorbed on the water oil interface by hydrogen bonds due to heteroatom...
Microscopic Investigation of the Effect of Low Salinity Waterflooding on Asphaltene Precipitation and Deposition Using Microfluidic Method
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahabodin (Supervisor) ; Mahani, Hassan (Supervisor)
Abstract
Water injection, as one of the conventional methods to increase the oil recovery factor has always been at the center of research works for Enhanced Oil Recovery (EOR). The conducted studies show that by controlling the amount and type of ions in the injected water, the recovery efficiency can be improved. In the meantime, most of the investigations are focused on the interaction between water/rock/oil to trace the wettability alteration. However, these interactions especially between the injected water and the oil phase, would lead to change of surface charge distribution of the reservoir rock. Besides, this effect can change some of the characteristics of the fluid phases, especially in...
Investigating the Effects of Different Parameters on Asphaltene Deposition Using Electrodeposition Technique
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahabeddin (Supervisor) ; Taghikhani, Vahid (Supervisor)
Abstract
Additional to Temperature, Pressure and Compositional changes of crude oils, Electro-kinetics and Electrical potential effects are also known as the most influencing parameters on Asphaltene deposition during oil production and processing.Mechanisms of electro-kinetics and asphaltene charge generation are very complex and unclear. In the previous studies on asphaltene precipitation and deposition, mostly electro-kinetics effects are ignored.While, recent studies show the great effects of electrical filed on asphaltene deposition during production and processing phase of crude oils.At reservoir porous medium and crude flow line, an electrical field can be developed along the length of the...
Investigation of Water Salinity Effect on Asphaltene Precipitation Using PC-SAFT EOS
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Saeed (Supervisor)
Abstract
In this study, for investigation of water salinity effect on asphaltene modeling, PC-SAFT equation of state has been used. All steps of modeling have been done by C sharp programming language software. Nghiem model has been used for modeling of asphalting pure solid. In this model, the heaviest component is split into two precipitating and nonprecipitation parts that their physical properties are the same in each part. Furthermore, to determine the exact mechanism of asphaltene precipitation, an oil model (Asphaltene+heptan+tuloene) in the presence of different water brine such as synthetic brine (with MgCl2, CaCl2, and Na2SO4 salts), seawater) ten and two times diluted), and formation water...
The impact of CO2 injection and pressure changes on asphaltene molecular weight distribution in a heavy crude oil: An experimental study
, Article Petroleum Science and Technology ; Volume 28, Issue 17 , 2010 , Pages 1728-1739 ; 10916466 (ISSN) ; Firoozinia, H ; Kharrat, R ; Ghazanfari, M. H ; Sharif University of Technology
Abstract
This work concerns observing the pressure as well as CO2 mole percentage effects on asphaltene molecular weight distributions at reservoir conditions. A high-pressure, high-temperature asphaltene measurement setup was applied, and the amount of precipitated asphaltene at different pressures as well as CO2 mole percentage in an Iranian heavy crude oil was measured. Moreover, the asphaltene molecular weight distributions during titration of crude oil with different n-alkanes were investigated. The gel permeation chromatography (GPC) apparatus was used for characterization of asphaltene molecular weight under different conditions. It has been observed that some thermodynamic changes such as...
The gas-oil interfacial behavior during gas injection into an asphaltenic oil reservoir
, Article Journal of Chemical and Engineering Data ; Volume 58, Issue 9 , 2013 , Pages 2513-2526 ; 00219568 (ISSN) ; Mehranbod, N ; Ayatollahi, S ; Sharif University of Technology
2013
Abstract
Oil displacement and recovery efficiency during gas injection depends on the competition between driving forces and capillary resistance that is governed by gas-oil interfacial behavior. Detailed study of the interfacial forces during gas injection is the main objective of this research work. The effects of injecting gas composition and the possibility of asphaltene precipitation in a wide pressure range were determined through comprehensive experimental study. This was performed by measurement of interfacial tension of a highly asphaltenic Iranian crude oil in three surrounding gas mediums. The results showed that as pressure increases, the rate to reach miscibility reduces in the vicinity...
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...
Prediction of asphaltene precipitation during solvent/CO2 injection conditions: A comparative study on thermodynamic micellization model with a different characterization approach and solid model
, Article Journal of Canadian Petroleum Technology ; Vol. 50, issue. 3 , March , 2011 , p. 65-74 ; Masihi, M ; Ghazanfari, M. H ; Kharrat, R ; Sharif University of Technology
Abstract
There are different thermodynamic models that have been applied for modelling of asphaltene precipitation caused by various reasons, such as solvent/CO2 injection and pressure depletion. In this work, two computer codes based on two different asphaltene precipitation thermodynamic models-the first being the thermodynamic micellization model with a different characterization approach and the second being the solid model-have been developed and used for predicting asphaltene precipitation data reported in the literature as well as in the obtained data for Sarvak reservoir crude, which is one of the most potentially problematic Iranian heavy oil reserves under gas injection conditions. For the...
Prediction of asphaltene precipitation during solvent/CO2 injection conditions: A comparative study on thermodynamic micellization model with a different characterization approach and solid model
, Article Journal of Canadian Petroleum Technology ; Volume 50, Issue 3 , 2011 , Pages 65-74 ; 00219487 (ISSN) ; Masihi, M ; Ghazanfari, M. H ; Kharrat, R ; Sharif University of Technology
Abstract
There are different thermodynamic models that have been applied for modelling of asphaltene precipitation caused by various reasons, such as solvent/CO2 injection and pressure depletion. In this work, two computer codes based on two different asphaltene precipitation thermodynamic models-the first being the thermodynamic micellization model with a different characterization approach and the second being the solid model-have been developed and used for predicting asphaltene precipitation data reported in the literature as well as in the obtained data for Sarvak reservoir crude, which is one of the most potentially problematic Iranian heavy oil reserves under gas injection conditions. For the...
Prediction of asphaltene precipitation during pressure depletion and CO2 injection for heavy crude
, Article Petroleum Science and Technology ; Vol. 28, issue. 9 , Mar , 2009 , p. 892-902 ; ISSN: 10916466 ; Kharrat, R ; Masihi, M ; Ghazanfari, M. , H ; Sharif University of Technology
Abstract
In this work, a thermodynamic approach is used for modeling the phase behavior of asphaltene precipitation. The precipitated asphaltene phase is represented by an improved solid model, and the oil and gas phases are modeled with an equation of state. The Peng-Robinson equation of state (PR-EOS) was used to perform flash calculations. Then, the onset point and the amount of precipitated asphaltene were predicted. A computer code based on the solid model was developed and used for predicting asphaltene precipitation data reported in the literature as well as the experimental data obtained from high-pressure, high-temperature asphaltene precipitation experiments performed on Sarvak reservoir...
Prediction of asphaltene precipitation during pressure depletion and CO2 injection for heavy crude
, Article Petroleum Science and Technology ; Volume 28, Issue 9 , Apr , 2010 , Pages 892-902 ; 10916466 (ISSN) ; Kharrat, R ; Masihi, M ; Ghazanfari, M. H ; Sharif University of Technology
2010
Abstract
In this work, a thermodynamic approach is used for modeling the phase behavior of asphaltene precipitation. The precipitated asphaltene phase is represented by an improved solid model, and the oil and gas phases are modeled with an equation of state. The Peng-Robinson equation of state (PR-EOS) was used to perform flash calculations. Then, the onset point and the amount of precipitated asphaltene were predicted. A computer code based on the solid model was developed and used for predicting asphaltene precipitation data reported in the literature as well as the experimental data obtained from high-pressure, high-temperature asphaltene precipitation experiments performed on Sarvak reservoir...
Precipitated asphaltene amount at high-pressure and high-temperature conditions
, Article Energy and Fuels ; Vol. 28, Issue. 3 , 2014 , pp. 1596-1610 ; ISSN: 08870624 ; Panuganti, S. R ; Taghikhani, V ; Pishvaie, M. R ; Chapman, W. G ; Sharif University of Technology
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. Essential information for such a study is the amount of asphaltenes that can precipitate and, hence, deposit. In this work, the perturbed chain form of the statistical associating fluid theory (PC-SAFT) is applied to predict the asphaltene precipitation onset condition as well as the amount of precipitate under pressure depletion and high-pressure and high-temperature gas injection conditions. Previous PC-SAFT asphaltene studies in crude oil required the compositional data for both flashed gas and flashed liquid. This...