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asphaltene-precipitation
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An experimental investigation of asphaltene precipitation during natural production of heavy and light oil reservoirs: The role of pressure and temperature
, Article Petroleum Science and Technology ; Volume 29, Issue 10 , 2011 , Pages 1054-1065 ; 10916466 (ISSN) ; Nakhli, H ; Kharrat, R ; Ghazanfari, M. H ; Sharif University of Technology
Abstract
Many oil reservoirs encounter asphaltene precipitation as a major problem during natural production. In spite of numerous experimental studies, the effect of temperature on asphaltene precipitation during pressure depletion at reservoir conditions is still obscure in the literature. To study their asphaltene precipitation behavior at different temperatures, two Iranian light and heavy live oil samples were selected. First, different screening criteria were applied to evaluate asphaltene instability of the selected reservoirs using pressure, volume, and temperature data. Then, a high pressure, high temperature filtration (HPHT) setup was designed to investigate the asphaltene precipitation...
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...
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...
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...
Experimental determination of equilibrium interfacial tension for nitrogen-crude oil during the gas injection process: The role of temperature, pressure, and composition
, Article Journal of Chemical and Engineering Data ; Vol. 59, issue. 11 , September , 2014 , p. 3461-3469 ; ISSN: 00219568 ; Ayatollahi, S ; Zolghadr, A ; Ghazanfari, M. H ; Masihi, M ; Sharif University of Technology
Abstract
Nitrogen has emerged as a competitive gas injection alternative for gas-based enhanced oil recovery processes in the past two decades. The injection of nitrogen into the reservoirs has improved the oil recovery efficiency in various oil reservoirs from heavy to volatile oils. As it is known, interfacial tension (IFT) plays a key role in any enhanced oil recovery process, particularly gas injection processes; therefore, its accurate determination is crucial for the design of any gas injection process especially at reservoir condition. In this study, an axisymmetric drop shape analysis (ADSA) was utilized to measure the equilibrium IFTs between crude oil and N2 at different temperature levels...
Phase behavior modeling of asphaltene precipitation for heavy crudes: A promising tool along with experimental data
, Article International Journal of Thermophysics ; Vol. 33, issue. 12 , December , 2012 , p. 2251-2266 ; ISSN: 0195928X ; Kharrat, R ; Masihi, M ; Ghazanfari, M. H ; Fadaei, S ; Sharif University of Technology
Abstract
Thermodynamic modeling is known as a promising tool for phase behavior modeling of asphaltene precipitation under different conditions such as pressure depletion and CO2 injection. 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, while the oil and gas phases are modeled with an equation of state. The 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 an improved solid model has been developed and used for predicting asphaltene precipitation data for one of...
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 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...
Phase behavior modeling of asphaltene precipitation for heavy crudes: A promising tool along with experimental data
, Article International Journal of Thermophysics ; Volume 33, Issue 12 , December , 2012 , Pages 2251-2266 ; 0195928X (ISSN) ; Kharrat, R ; Masihi, M ; Ghazanfari, M. H ; Fadaei, S ; Sharif University of Technology
2012
Abstract
Thermodynamic modeling is known as a promising tool for phase behavior modeling of asphaltene precipitation under different conditions such as pressure depletion and CO2 injection. 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, while the oil and gas phases are modeled with an equation of state. The 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 an improved solid model has been developed and used for predicting asphaltene precipitation data for one of...
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...
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....
Experimental investigation and thermodynamic modeling of asphaltene precipitation
, Article Scientia Iranica ; Volume 18, Issue 6 , December , 2011 , Pages 1384-1390 ; 10263098 (ISSN) ; Ghotbi, C ; Taghikhani, V ; Shahrabadi, A ; Sharif University of Technology
2011
Abstract
Asphaltene precipitation may occur during pressure depletion or gas injection processes in a reservoir. This phenomenon is an important problem during oil production, because it can result in formation damage and the plugging of wellbore and surface facilities. In this work, the precipitation of asphaltenes in an Iranian crude oil, under different pressures, is measured, using an experimental set up based on high-pressure isothermal expansion and also atmospheric titration. For the particular oil investigated, compositional data, precipitation phase diagrams, and bubble point and onset pressures are reported. Also, in this work, the Perturbed Chain form of the Statistical Associating Fluid...
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...
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,...
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 ; 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...
Experimental study of solvent flooding to heavy oil in fractured five-spot micro-models: The role of fracture geometrical characteristics
, Article Journal of Canadian Petroleum Technology ; Volume 49, Issue 3 , 2010 , Pages 36-43 ; 00219487 (ISSN) ; Kharrat, R ; Ghazanfari, M. H ; Sharif University of Technology
2010
Abstract
The solvent-based process appears to be an increasingly feasible technology for the extraction of heavy oil reserves. However, there is a lack of fundamental understanding of how fracture geometrical characteristics control the oil recovery efficiency in this type of enhanced oil recovery (EOR) technique. In this work, a series of experiments were performed whereby the pure and mixed hydrocarbon solvents (HCS) displaced heavy oil in fractured five-spot glass micro-models. Successive images of the solvent injection process were recorded. The oil recovery factor, as a function of injected pore volume of solvents, was measured using image analysis of the provided pictures. It has been observed...
Kinetics of asphaltene aggregation phenomena in live oils
, Article Journal of Molecular Liquids ; Volume 222 , 2016 , Pages 359-369 ; 01677322 (ISSN) ; Rashidi, F ; Ghazanfari, M. H ; Mousavi Dehghani, S. A ; Sharif University of Technology
Elsevier
Abstract
The thorough knowledge of the asphaltene aggregation phenomena and pressure/temperature related kinetics is helpful for accurate prediction/control of the asphaltene issues in all facets of petroleum production/processing. However, characterizing the asphaltene aggregation phenomena in live oils at high pressure-high temperature conditions is not well discussed in the available literature. In this work, the asphaltene aggregation phenomena as well as the kinetics of aggregation at different levels of pressure and temperature are investigated in light and heavy live oils using high pressure microscope. The results are presented and discussed in terms of asphaltene onset pressure, aggregates...
Investigation of gas injection flooding performance as enhanced oil recovery method
, Article Journal of Natural Gas Science and Engineering ; Volume 29 , 2016 , Pages 37-45 ; 18755100 (ISSN) ; Lashkar Bolooki, M ; ZeinolabediniHezave, A ; Ayatollahi, S ; Sharif University of Technology
Elsevier
Abstract
Asphaltene precipitation and deposition within the reservoir formation is one of the main concerns during enhanced oil recovery (EOR) processes especially during the gas injection. In the current study, different aspects of carbon dioxide (CO2) and nitrogen (N2) injection in the reservoir, was thoroughly examined. The feasibility of using these gases as the injection gas was explored using Bayesian network-based screening method. After recombination and preparation of the live crude oil, precipitation of asphaltene using vanishing interfacial tension (VIT) method and core flooding experimentation was examined. Besides, swelling test was utilized to investigate the effect of CO2 and N2...