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Monitoring the role of fracture geometrical characteristics on fingering initiation/development during heavy oil miscible displacements in fractured porous media
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Vol. 35, issue. 12 , Aug , 2010 , p. 1129-1139 ; ISSN: 15567036 ; Ghazanfari, M. H ; Masihi, M ; Kharrat, R ; Sharif University of Technology
Abstract
Finger initiation/development at fluid-fluid interface during miscible floods can cause poor displacement efficiency, which is undesirable in enhanced oil recovery processes. In this work, a series of hydrocarbon injection experiments performed on 5-spot glass micromodels that were initially saturated with the heavy crude oil. The fractured micromodels with different fracture geometrical characteristics were used in the tests. High quality image analysis was applied to determine the fluid flow behavior, solvent front movement, and viscous fingering associated with solvent movement in matrix and fractures. Observations showed that higher solvent dispersion in the fractures rather than matrix...
Understanding the polydisperse behavior of asphaltenes during precipitation
, Article Fuel ; Vol. 117, issue. PART A , 2014 , pp. 206-217 ; Panuganti, S. R ; Taghikhani, V ; Pishvaie, M. R ; Chapman, W. G ; Sharif University of Technology
Abstract
Asphaltenes are a polydisperse fraction of the crude oil, the phase behavior of which is significantly affected by the changes in pressure, temperature and composition. The focus of this study is to model the polydisperse asphaltenes' precipitation onset condition and the amount of precipitate from solvent-diluted crude oils using the Perturbed Chain form of the Statistical Associating Fluid Theory (PC-SAFT) over a wide range of crude oil density. Heavy oil and bitumen production can involve diluting with paraffinic solvents. Different fractions of the polydisperse asphaltenes thus precipitated are predicted and when compared to the experimental data show a remarkable matching for different...
Monitoring the role of fracture geometrical characteristics on fingering initiation/development during heavy oil miscible displacements in fractured porous media
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 35, Issue 12 , Aug , 2013 , Pages 1129-1139 ; 15567036 (ISSN) ; Ghazanfari, M. H ; Masihi, M ; Kharrat, R ; Sharif University of Technology
2013
Abstract
Finger initiation/development at fluid-fluid interface during miscible floods can cause poor displacement efficiency, which is undesirable in enhanced oil recovery processes. In this work, a series of hydrocarbon injection experiments performed on 5-spot glass micromodels that were initially saturated with the heavy crude oil. The fractured micromodels with different fracture geometrical characteristics were used in the tests. High quality image analysis was applied to determine the fluid flow behavior, solvent front movement, and viscous fingering associated with solvent movement in matrix and fractures. Observations showed that higher solvent dispersion in the fractures rather than matrix...
Experimental investigation of microscopic/macroscopic efficiency of polymer flooding in fractured heavy oil five-spot systems
, Article Journal of Energy Resources Technology, Transactions of the ASME ; Volume 135, Issue 3 , 2013 ; 01950738 (ISSN) ; Ghazanfari, M. H ; Parvazdavani, M ; Morshedi, S ; Sharif University of Technology
2013
Abstract
This paper concerns on experimental investigation of biopolymer/polymer flooding in fractured five-spot systems. In this study, a series of polymer injection processes were performed on five-spot glass type micromodels saturated with heavy crude oil. Seven fractured glass type micromodels were used to illustrate the effects of polymer type/concentration on oil recovery efficiency in presence of fractures with different geometrical properties (i.e., fractures orientation, length and number of fractures). Four synthetic polymers as well as a biopolymer at different levels of concentration were tested. Also a micromodel constituted from dead-end pores with various geometrical properties was...
The determination of effective diffusivity coefficients in a solvent gas heavy oil system for methane
, Article Petroleum Science and Technology ; Volume 30, Issue 24 , 2012 , Pages 2582-2593 ; 10916466 (ISSN) ; Dadvar, M ; Kharrat, R ; Ghazanfari, M. H ; Sharif University of Technology
2012
Abstract
In this investigation, an accurate high pressure and temperature diffusion setup was applied to measure the diffusion coefficients of methane in Iranian heavy oils in presence and absence of porous media by using the pressure-decay method. The solvent diffusivity in heavy oil was determined by both graphical and numerical methods. In addition, the effects of the porous medium and the temperature on the molecular diffusion coefficient of the solvent gas in the liquid phase were discussed and finally, using experimental data, a functionality dependence of molecular diffusivity on temperature and porous medium characteristics was proposed
The effect of geometrical properties of reservoir shale barriers on the performance of Steam-assisted Gravity Drainage (SAGD)
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 34, Issue 23 , 2012 , Pages 2178-2191 ; 15567036 (ISSN) ; Sharif University of Technology
Abstract
Many bitumen reservoirs contain shale layers of varying thickness, lateral extent, and frequency. These shale layers, depending on their size, vertical and horizontal locations, and continuity throughout the reservoir, may act as a flow barrier and severely reduce vertical permeability of the pay zone and slow down the steam-assisted gravity drainage steam chamber development. Therefore, to improve productivity in these reservoirs, understanding of the effects of reservoir heterogeneities has become necessary. This work presents numerical investigation of the effects of shale barriers on steam-assisted gravity drainage performance when applied to produce mobile heavy oil. The most concern of...
Quantifying the role of pore geometry and medium heterogeneity on heavy oil recovery during solvent/Co-solvent flooding inwater-wet systems
, Article Journal of Porous Media ; Volume 14, Issue 4 , 2011 , Pages 363-373 ; 1091028X (ISSN) ; Kharrat, R ; Ghazanfari, M. H ; Vossoughi, S ; Sharif University of Technology
Abstract
Porous medium characteristics (e.g., pore geometry and medium heterogeneity) as well as the chemical nature of the co-solvents crucially affect the oil displacement efficiency during solvent flooding processes. In this work, initially saturated models with heavy crude oil were used to perform a series of solvent injection experiments. Several onequarter five-spot micromodels with pre-designed pore geometry were constructed and used. In addition, rock-look-alike flow patterns generated from thin sections of sandstone and dolomite reservoir rocks were etched onto glass plates to form micromodels mimicking the pore geometry and heterogeneity of these rocks. Four different groups of chemicals...
Worm-like micelles:a new approach for heavy oil recovery from fractured systems
, Article Canadian Journal of Chemical Engineering ; Volume 93, Issue 5 , 2015 , Pages 951-958 ; 00084034 (ISSN) ; Saidian, M ; Mavaddat, M ; Ghazanfari, M. H ; Kharrat, R ; Rashtchian, D ; Sharif University of Technology
Wiley-Liss Inc
2015
Abstract
In this work, a new type of flooding system, "worm-like micelles", in enhanced heavy oil recovery (EOR) has been introduced. Application of these types of surfactants, because of their intriguing and surprising behaviour, is attractive for EOR studies. Fundamental understanding of the sweep efficiencies as well as displacement mechanisms of this flooding system in heterogeneous systems especially for heavy oils remains a topic of debate in the literature. Worm-like micellar surfactant solutions are made up of highly flexible cylindrical aggregates. Such micellar solutions display high surface activity and high viscoelasticity, making them attractive in practical applications for EOR. In this...
An experimental and numerical investigation of solvent injection to heavy oil in fractured five-spot micromodels
, Article Petroleum Science and Technology ; Volume 28, Issue 15 , 2010 , Pages 1567-1585 ; 10916466 (ISSN) ; Ghazanfari, M. H ; Kharrat, R ; Vossoughi, S ; Sharif University of Technology
2010
Abstract
In this work a series of solvent injection experiments was conducted on horizontal glass micromodels at several fixed flow rate conditions. The micromodels were initially saturated with heavy crude oil. The produced oil as a function of injected volume of solvents was measured using image analysis of the continuously provided pictures. In order to investigate the macroscopic behavior of the process in different media, several fractured, with constant width, and nonfractured five-spot micromodels were designed and used. The measured data have also been used for verifying and developing a simulation model that was later used for sensitivity analysis of some parameters that affect oil recovery....
Thermogravimetric analysis and kinetic study of heavy oil pyrolysis
, Article Petroleum Science and Technology ; Volume 34, Issue 10 , 2016 , Pages 911-914 ; 10916466 (ISSN) ; Hami, M. R ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
ABSTRACT: Pyrolysis, so-called devolatilization, is one of the first steps of all thermochemical processes occurring in an inert atmosphere. The authors discuss the main kinetic features of heavy oil pyrolysis, on the basis of the data derived m from a TGA analysis and by using a kinetic model. The samples were heated over a range of temperature from 400 K to 430°C at various heating rates between 10 and 80°C/min. Experimental results showed that the effect of time is considerable in the case of tar conversion, compared to char and gases
Comparison of the effect of temperature on asphaltene destabilisation in light and heavy live oils
, Article International Journal of Oil, Gas and Coal Technology ; Volume 16, Issue 4 , 2017 , Pages 342-362 ; 17533317 (ISSN) ; Rashidi, F ; Mousavi Dehghani, S. A ; Ghazanfari, M. H ; Sharif University of Technology
Abstract
The main objective of this study is to investigate the effect of temperature on asphaltene destabilisation (precipitation/aggregation) in live oils at elevated pressure conditions. Here, the asphaltene related experiments were performed using solid detection systems, high pressure microscope, and high pressure-high temperature filtration apparatuses in two Iranian light and heavy live oils with different characteristics and stability. The obtained results were interpreted in terms of asphaltene onset pressure, size distribution and average diameter of the aggregates, fractal analysis of the aggregates structures, and the amount of asphaltene precipitation. As well, the results of the...
Simulation of Heat & Momentum Balance of Vacuum Bottom Flow in Thermal Cracking Fired Heater
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Fathollah (Supervisor)
Abstract
The delayed coking process is one of the common thermal process technique that used to improve the quality of heavy oil. In this process, heavy feeds such as vacuum residues have been heated in the furnace to temperatures up to the 480-500 °C. For the cracking reactions the heated feed have been sent to the drum that is placed after the furnace. Since the reactions begin inside the furnace and coke is one of the products, deposited on the wall of the tube. With the deposition of coke on the tube wall and the reduction of heat transfer, the temperature of the tube have been increased with the increasing of the flame temperature to save constant heat flux. Therefore, the study of thermal...
Phase behavior and interfacial tension evaluation of a newly designed surfactant on heavy oil displacement efficiency; effects of salinity, wettability, and capillary pressure
, Article Fluid Phase Equilibria ; Vol. 396, issue , June , 2015 , p. 20-27 ; ISSN: 03783812 ; Masihi, M ; Ayatollahi, S ; Sharif University of Technology
Abstract
This work aims to discuss the results of wide ranges of laboratory investigations to evaluate the performance of a newly-formulated surfactant for heavy oil reservoirs in order to improve the microscopic sweep efficiency after water flooding processes. In the first part, the specific behavior of the formulated surfactant including its salinity tolerance, interfacial tension, and optimum performance window was determined. Then, the application of surfactant solutions in real sandstone reservoir rocks was assessed for both oil-wet and water-wet cases. Besides, the effect of changing the capillary and viscous forces and interfacial tension on the residual phase saturations were characterized....
Toe-to-heel air injection: Investigation of the effect of fractures geometrical properties on process performance
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 33, Issue 22 , Sep , 2011 , Pages 2067-2077 ; 15567036 (ISSN) ; Kharrat, R ; Ghotbi, C ; Sharif University of Technology
Abstract
Toe to heel air injection has been studied on non-fractured sandstone models and is found to be a promising enhanced oil recovery method for certain heavy oil reservoirs, such as those in Canada, but its applicability on fractured reservoirs, such as those in the Middle East, is not investigated yet. The objective of this article is to evaluate the effect of fractures geometrical parameters, such as fracture density, orientation, and location, on the performance of the process in laboratory scale. Simulation results showed that toe-to-heel air injection is more applicable on highly networked fractured reservoirs, such as those that occur in Persian Gulf coast compared to lower density...
The effect of fractures' geometrical properties on the recovery mechanism of the top-down in situ combustion process
, Article Petroleum Science and Technology ; Volume 30, Issue 2 , Feb , 2011 , Pages 147-158 ; 10916466 (ISSN) ; Kharrat, R ; Sharif University of Technology
2011
Abstract
The top-down in situ combustion (ISC) involves the stable propagation of the combustion front from the top vertical injector to the bottom horizontal producer. Apart from laboratory studies in conventional sandstones, no application of the process in fractured carbonates has been addressed yet. The authors modified a successful combustion tube history matched model of an Iranian low-permeable heavy oil reservoir called Kuh-E-Mond to investigate the feasibility of ISC in fractured carbonate reservoirs mimicking block-scale combustion cells. Effects of fractured geometrical properties such as orientation, location, extension, density, spacing, and dispersion were considered. Results confirmed...
Preliminary considerations on the application of toe-to-heel steam flooding (THSF): Injection well-producer well configurations
, Article Chemical Engineering Research and Design ; Volume 89, Issue 11 , 2011 , Pages 2365-2379 ; 02638762 (ISSN) ; Yadali Jamaloei, B ; Sharif University of Technology
Abstract
This work examines the operational parameters that may influence the performance of toe-to-heel steamflooding in a laboratory-scale simulation model built on the basis of the fluid and rock samples from a fractured, low-permeable, carbonate heavy oil reservoir in Southwestern Iran, called KEM (Kuh-e-Mond). Using vertical (V) or horizontal (H) injectors (I) and producers (P), the effects of different well configurations including VIVP, VIHP, 2VIHP, VI2HP, HIHP, and HI2HP, injectors' traversal distance, producers' traversal distance, and horizontal producer length have been investigated. In summary, the results show that 2VIHP scheme performs best in terms of oil recovery and areal/volumetric...
Experimental investigation of gas-heavy oil molecular diffusion coefficient in porous media: Experimental results for CO2 in Iranian Crudes
, Article Defect and Diffusion Forum ; Volume 312-315 , 2011 , Pages 1049-1054 ; 10120386 (ISSN) ; 9783037851173 (ISBN) ; Kazemeini, M ; Kharrat, R ; Ghazanfari, M. H ; Salehi, A ; Sharif University of Technology
Abstract
Molecular diffusion of gases in crude oils plays a crucial role in several oil recovery processes especially in cold-based production process. However, experimental data concerning CO2 diffusivity in heavy oils due to the tedious nature of diffusivity measurements are relatively rare in the open literature. In this work, a comprehensive experimental investigation of the effective molecular diffusion determination of CO2-heavy oil systems in homogeneous porous media was studied. The so-called pressure decay method was applied to measure the molecular diffusivity of carbon dioxide in heavy oil. Furthermore, effect of various parameters such as initial pressure, temperature and porous media on...
Phase behavior and interfacial tension evaluation of a newly designed surfactant on heavy oil displacement efficiency; effects of salinity, wettability, and capillary pressure
, Article Fluid Phase Equilibria ; Volume 396 , 2015 , Pages 20-27 ; 03783812 (ISSN) ; Masihi, M ; Ayatollahi, S ; Sharif University of Technology
Elsevier
2015
Abstract
This work aims to discuss the results of wide ranges of laboratory investigations to evaluate the performance of a newly-formulated surfactant for heavy oil reservoirs in order to improve the microscopic sweep efficiency after water flooding processes. In the first part, the specific behavior of the formulated surfactant including its salinity tolerance, interfacial tension, and optimum performance window was determined. Then, the application of surfactant solutions in real sandstone reservoir rocks was assessed for both oil-wet and water-wet cases. Besides, the effect of changing the capillary and viscous forces and interfacial tension on the residual phase saturations were characterized....
Experimental investigation of heavy oil recovery by continuous/WAG injection of CO2 saturated with silica nanoparticles
, Article International Journal of Oil, Gas and Coal Technology ; Volume 9, Issue 2 , 2015 , Pages 169-179 ; 17533317 (ISSN) ; Khezrnejad, A ; Shahrokhi, O ; Ghazanfari, M. H ; Vossoughi, M ; Sharif University of Technology
Inderscience Enterprises Ltd
2015
Abstract
In this work, application of CO2 saturated with silica nanoparticles in continuous/water alternating gas (WAG) injection for heavy oil recovery was investigated which has been rarely attended in the available literature. Core displacement tests were conducted to monitor heavy oil recovery in both continuous and WAG injection schemes. It has been observed that for continuous nano-saturated CO2 injection, the oil recovery is higher than pure CO2 injection. This observation might be explained by alteration of rock wettability to a more water-wet condition. In WAG injection scheme, water breakthrough happened later in nano-saturated CO2 than pure CO2 injection. This delayed water breakthrough...
Monitoring wettability alteration by silica nanoparticles during water flooding to heavy oils in five-spot systems: A pore-level investigation
, Article Experimental Thermal and Fluid Science ; Vol. 40, issue , July , 2012 , p. 168-176 ; ISSN: 08941777 ; Mohammadi, S ; Ghazanfari, M. H ; Kharrat, R ; Masihi, M ; Sharif University of Technology
Abstract
It is well known that the displacement efficiency of EOR processes is mainly affected by wettability of porous medium; however, the role of nanoparticles on wettability alteration of pores surfaces remains a topic of debate in the literature. Furthermore, a little is known about how the dispersed silica nanoparticles affect the microscopic/macroscopic recovery efficiency of heavy oils during common immiscible EOR processes such as water flooding. In this study, a series of injection experiments was performed on five-spot glass micromodel which is initially saturated with the heavy oil. Distilled water and dispersed silica nanoparticles in water (DSNW) at different values of weight percent...