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soltani-soulgani--bahram
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A novel method for mitigation of asphaltene deposition in the wellstring
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 29, Issue 2 , 2010 , Pages 131-142 ; 10219986 (ISSN) ; Rashtchian, D ; Tohidi, B ; Jamialahmadi, M ; Sharif University of Technology
2010
Abstract
Asphaltene precipitation and deposition is a serious problem in many Iranian fields. The deposited asphaltene results in partial or total blockage of the wellbore and wellstring reducing or completely seizing oil production. This paper studies the asphaltene problem and mitigation methods in wellstring systematically. It presents new approach based on the combination of thermodynamic modeling of asphaltene precipitation with hydrodynamic well modeling. The developed model is capable to determine the asphaltene precipitation and deposition interval through the wellstring. Therefore, it could study the effect of hydrodynamic parameters such as wellhead pressure, well flow-rate and tubing size...
Effect of Kinetic and Hydrodynamic on Asphaltene Deposition in Porous Media
, Ph.D. Dissertation Sharif University of Technology ; Rashtchian, Davoud (Supervisor) ; Jamialahamdi, Mohammad (Supervisor) ; Tohidi, Bahman (Supervisor)
Abstract
Asphaltene are the heaviest components if some crude oil which are in thermodynamic equilibrium. Any change in the equilibrium condition including change in temperature, pressure or composition may render asphaltene to come out of solution and precipitate. Asphaltene precipitation and deposition is one of the main problems in some of the oil fields. Precipitated asphaltene may deposit in the reservoir, near wellbore, wellstring, transport pipeline and surface facilities. In porous media, the deposited asphaltene over the surface and/or across pore throat can severely reduce the effective permeability and results in decreasing of the oil production. Also, the deposited asphaltene results in...
Application of ANFIS-GA algorithm for forecasting oil flocculated asphaltene weight percentage in different operation conditions
, Article Petroleum Science and Technology ; Volume 36, Issue 12 , 2018 , Pages 862-868 ; 10916466 (ISSN) ; Soltani Soulgani, B ; Bemani, A ; Sharif University of Technology
Taylor and Francis Inc
2018
Abstract
Asphaltene which cover range of 1% to over 10% of oil by weight, is well-known as most problematic part of oil that can deposit during production in reservoir, well tubing, and surface production lines, and consequently impose a serious restriction on production which in turn increases total cost of entire operation. Through decades an extensive research has been performed in order to identify asphaltene molecular structure, its behavior at different condition, and its separation mechanism from oil. One of most critical parameter associated with asphaltene precipitation modeling is flocculated asphaltene weight percentage in oil at given operation condition. In this study, to eliminate cost...
Study of Supramolecular Chemistry of Fullerene (C60) with Azobenzene Tweezer Linking to Biaza-Crown Macrocycles Coordinated to Zinc Tetraphenylporphyrin
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
In this project, in continuation of a PhD resreach undertaken in this research group in 2017, the synthesis and study of two new tweezer and linker molecule bearing azobenzene moiety were carried out, characterized by applying IR spectroscopy, ¹H and ¹³C {¹H} NMR, fluorescence spectroscopy, UV-visible spectroscopy, elemental analysis and X-ray crystallography. Firstly, interaction of T2 with meso-tetraphenylporphyrinato zinc(II) and aluminium tetraphenylporphyrinato were studied using the fluorescence spectroscopy. The formation constant of T2 in cis and trans isomer with ZnTPP was measured as 5.1(±0.4) ×108 and 2.0×108(±1074) dm6mol-2, respectively. The formation constant of T2 in with...
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...
Integrated modelling methods for asphaltene deposition in wellstring
, Article Journal of the Japan Petroleum Institute ; Volume 47, Issue 1 , 2004 , Pages 27-31 ; 13468804 (ISSN) ; Rashtchian, D ; Tohidi, B ; Jamialahmadi, M ; Sharif University of Technology
2004
Abstract
Asphaltene precipitation and deposition is one of the main problems in some of the oil fields. The deposited asphaltene results in partial or total blockage of the wellstring and reducing or completely seizing oil production. Asphaltene deposition problems have been experienced in the field for a long time. Although, the asphaltene precipitation has been studied thoroughly and different parameters that effects this process has been investigated but little work has been carried out in the asphaltene deposition across the production system of flowing oil well. This paper introduces a new comprehensive model for description of asphaltene deposition behavior in wellstring. The mechanisms of...
Synthesis of C60 and Endohedral Fullerenes in New Multi-Channel Arc Reactor Equipped with Horizontal Graphite Electrodes
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
One of the most common methods of producing fullerenes is electric arc vaporization of graphite. Due to the low yield and purity of the nanoparticles in this method, the synthesis and isolation of the area research is important. In this work, the production was improved in a multi-channel arc reactor in which having horizontal graphite electrodes. The influence of various operational parameters such as pressure of inert gas, spark time, interval time between two sparks, voltage and current were completely optimized. Moreover, the prominent advantage of the new reactor was increasing the number of manufacturing units, at least from one to three, which the production of fullerene was...
Comparative Study on [60]Fullerene and Cu(II) Complexation with O2N3-Azacrowns
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
The purpose of this project is to synthesis of O2N3-azacrown ligands with 17 to 21 membered ring and investigation of their interaction with C60 according to increase ring size. These macrocyclic ligands can be used in C60 purification. In this project, change in macrocyclic cavity for finding the best macrocycle with appropriate cavity to C60 size has been considered. Firstly, five O2N3-azacrown ligands were synthesized and characterized by NMR spectroscopy and elemental analysis. Interaction of these ligands were considered by electronic spectroscopy applying Benesi-Hildebrand equation. According to the results, it was found that the best macrocycle for formation of stable complex with...
(Synthesis and Comparative Study on Complexation of OxNy-Azacrown Macrocyclic Ligands with [60] Fullerene and Cu(II
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
In our previous work in this laboratory, macrocycle containingO_2 N_2 and O_2 N_3- donor set with various ring size were synthesized. The intraction of macrocyles with [60]fullerene were determined. In this research, we synthesized 22-membered aza-crown macrocycle ligand containing O_4 N_2- donor set and characterized by NMRspectroscopy. The intraction of macrocycle with [60]fullerene were also investigated by UV-Visible spectroscopy. The formation constant was determined applying Benesi--Hildebrand equation. The result has been showed that O_4 N_2 macrocyle had better complexation with [60]fullerene in comparision of O_2 N_3 and O_2 N_2 donor sets. Then, the interaction of O_4 N_2 with...
Synthesis and Electrochemical Study of Endohedral Fullerenes Prepared by Arc Vaporizing Method
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
Fullerenes are molecular solid materials which are composed of 3D closed shell carbon-only structure. As soon as mass production of fullerenes was performed, the synthesis and characterization of endohedral fullerenes having at least one non-carbon element in the hollow fullerene cage, was started (in which about 30 atoms inserted in it so far). Furthermore, because of low efficiency and purity of these nano-particles, nowadays characterization of fullerenes is one of the most important research fields. In this project, we firstly optimized the fullerene production parameters in an arc discharge reactor to reach convenient efficiency. Then, the synthesis of endohedral fullerene by vaporizing...
Extractive Summarization based Cognitive Science of Human Mind for Narrative Text
, M.Sc. Thesis Sharif University of Technology ; Vazirnezhad, Bahram (Supervisor)
Abstract
In this project, a summarization system, which works for narrative text, based on cognitive science has been designed. Its results due to its different approach have been satisfactory. Since summarization has a direct relationship with comprehension of text. This system has been designed based on situational model, a famous theory related to comprehension of text.According to this theory, as human read a text, they extract five features for comprehension of text. The features are temporality, place, causality, protagonists, and intentionality. The make a frame based on these features. Event- Indexing model pays attention to all of these features, so it has been used for the summarization...
Synthesis of Azacrown Macrocyclic Ligand with Pendant Arms and Study of Their Complexation with [60] Fullerene and Cu(II) Cation
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
In this research, four N2O2–azacrown macrocyclic ligands with naphthalene pendant arms (L1-L4) were synthesized using direct synthesis. The products were characterized applying 1H and 13C {1H} NMR spectroscopy, IR and Mass spectrometry. Interaction of these ligands with [60]fullerene and Cu(II) were monitored respectively by fluorescent as well as UV-vis spectroscopy and applying Benesi-Hildebrand equation. These intercations were compared with N2O2 macrocyclic ligands in previous experiments in terms of their calculated association constants (Ka). According to our results, the presence of naphthalene pendant arm groups led to increase the interaction with [60]fullerene compared to the...
Synthesis of Azacrown Ethers N2O2 Ligands Substituted on the Ullerene and Investigation of Its Coordination Properties
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
The goal of this project was study on coordination behavior of the 14-membered macrocyclic ligand of type N2O2 aza-crown while it is attached to fullerene C60 nano-particle. For this purpose, firstly the macrocyclic ligand (Fig 3-1, L1) was synthesized and then was reacted with C60 (Fig 3-1, L2) of which the product was characterized by elemental analysis. Since the product was insoluble in any solvents, further study on its coordination chemistry was impossible. In a second procedure, the macrocyclic ligand was reacted with benzylbromide. The reaction mixture gave two macrocyclic ligands with different number of benzylic pendant groups (Fig 3-1, L3-L4). The products were separated by column...
Study of NxOy Macrocycles Bearing Peripheral Functional Groups as Axial Ligands of Zinc Tetraphenylporphyrin
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
In this project, M2 macrocyclic ligand, bearing three pyridine side arms (3p) was synthesized and characterized by employing elemental analysis and 1H NMR, 13C NMR and IR methods. The interaction of 3p with zinc tetraphenylporphyrin was investigated, using fluorescence and UV-vis spectroscopy in solution phase. The observed quenching in the fluorescence spectrum alongside Q band shift in UV-vis spectrum indicate on the interaction of 3p with ZnTPP. The formation constant for these interactions in 1:1 ratio was calculated 10100 M-1, employing fluorescence method. The formation constant was calculated 630 M-1 for 1:2 ratio for 3p:ZnTPP. Having 1:2 ratio 3pZnTPP was also synthesized and...
Synthesis and Comparative Study on Complex Formation of Azo-bearing Nitrogen-Donor Macrocyclic Ligands with Fullerene C60 and Cu(II) Cation
, Ph.D. Dissertation Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
In the present research, a series of bimacrocyclic tweezer anchored through azobenzene moiety were synthesized and characterized by applying IR spectroscopy, 1H and 13C{1H} NMR, fluorescence spectroscopy, UV-visible spectroscopy, mass spectrometry and elemental analysis and in some cases by X-ray crystallography. Firstly, UV-visible spectroscopy established that the irradiation of the tweezers with UV light promoted the trans to cis isomerization. On the other hand, thermal cis-trans isomerization behavior of the azobenzene moiety in tweezers was surveyed in which the cis isomers were formed of the heating at 50 oC for 5 minutes. Where the -OH group was replaced with 4-toluenesulfonyl...
Synthesis of Aza-Crown Macrocyclic Ligand Appended with Side Arms and Study of their Coordination and Supramolecular Chemistry with Cu2+ and C60
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
In the present study, the coordination chemistry of an O4N4-tetrabenza-crown ether macrocyclic ligand L1 with M2+ (M= Cu, Cd, Hg, and Pb) was investigated by employing UV-visible, 1H-NMR spectroscopy in their solutions. According to the association constants calculated by 1H-NMR titrations, the complex formation stability for these closed shell cations was found in a series of Pb > Hg > Cd, leading to the larger cation, the better accommodation with L1. Moreover, the supramolecular interaction of L1 with fullerene C60 was also assessed by UV-visible spectroscopy. Meanwhile, the structure of [Cd(1)]2+ complex was determine by X-ray crystallographic method in their solid state. A square...
Synthesis and Study of Coordination and Supramolecular Chemistry of N2O4-Azacrown Macrocyclic Ligands with Cu(II) and [60]Fullerene
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
By considering previous experiments undertaken in our laboratory on OXNY (X=2,4 Y=2,3) azacrown complexes with [60]fullerene, it was found that factors such as the macroring size, type and number of the donor groups in these macrocyclic ligands had significant effects on their selectivity towards [60]fullerene complexation. In this research, 20 and 24-membered N2O4-azacrown macrocyclic ligands was synthesized and characterized applying 1H and 13C NMR spectroscopy, FT-IR as well as CHN elemental analysis. Interaction of these ligands with [60]fullerene and Cu(II) were monitored by UV-vis spectroscopy and applying Benesi-Hildebrand equation. The association constants (Ka) values related to the...
Synthesis and Coordination Chemistry Study of NxO2 Aza-Crown Macrocycle Derivatives in Aqueous Solution
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
In this study, a water-soluble Aza-crown N2O2 ligand with a two-carboxylate side arm was synthesized and characterized by 1H-NMR, 13C-NMR, UV-vis, fluorescence, mass spectrometry, and elemental analysis. Unlike EDTA, this ligand is soluble in acidic solution. Fluorescence spectroscopy did not show significant selectivity except for calcium (and to some extent strontium) and copper cations. Due to the similarity of the aminocarboxylate groups with some chelating agents, the ability of this macrocyclic ligand as a scale inhibitor was investigated using the NACE-TM374 standard test method. In these tests, the new arm ligand showed significant protection against the presence of calcium sulfate....
Synthesis of N2O2N Azacrown Macrocyclic Ligands and Comparative Study on the Complexation of Ligands with [60]Fullerene and Cu(II)
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
By considering previous experiments undertaken in our laboratory on O2Nx (x=2,3) azacrown complexes with [60]fullerene, it was found that factors such as the macroring size, type and number of the donors groups in these macrocyclic ligands had significant effects on their selectivity towards [60]fullerene complexation. In this research, three N2O2N–azacrown macrocyclic ligand having uniform distribution of nitrogen atoms in macroring was synthesized using direct synthesis and high dilution method. The products were characterized applying 1H and 13C NMR spectroscopy as well as elemental analysis. Interaction of these ligands with [60]fullerene and Cu(II) were monitored by UV-vis spectroscopy...
Comparative Study of Anti-oxidant Property of Fullerene C60 and its Amine Derivatives: the Effect of Transition Metal Complexes
, M.Sc. Thesis Sharif University of Technology ; Ghanbari, Bahram (Supervisor)
Abstract
Since the discovery of fullerene C60, its chemical and physical properties have been a hot topic in the field of research. For the past two decades remarkable developments achieved in the field of fullerenes chemistry. The aim of this study is comparative study of antioxidant property of fullerene C60 and its amine derivatives and the effect of transition metal complexes. At the outset the anti-oxidative property of fullerene C60 and its amine derivatives explored and it was found that by increasing the chain length of amines, the anti-oxidative property of aminofullerenes increased respectively. In next step the effect of CoSALEN complex on anti-oxidative property of fullerene was...