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Experimental Investigation of Asphaltene Precipitation and Deposition in Enhanced Oil Recovery by Low Salinity Waterflooding
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahabadin (Supervisor) ; Fatemi, Mobin (Supervisor)
Abstract
Asphaltenes are a polydisperse mixture of the heaviest and most polarizable fractions of the crude oil. They are defined according to their solubility properties as being soluble in aromatic solvents but insoluble in light paraffin solvents. Asphaltenes are usually responsible for many problems like wettability changes of the reservoir rock, pore clogging in the reservoir porous matrix and fouling in wellbore tubing and production surface facilities. Most of the studies in the literature, addressing the asphaltene precipitation and deposition (APD), are investigating natural depletion or gas injection process such as CO2 flooding. These studies show that asphaltene deposition and...
Nanotechnology-assisted EOR techniques: New solutions to old challenges
, Article Society of Petroleum Engineers - SPE International Oilfield Nanotechnology Conference 2012 ; 2012 , Pages 382-396 ; 9781622761104 (ISBN) ; Zerafat, M. M ; Sharif University of Technology
SPE
2012
Abstract
Enhanced Oil Recovery techniques are gaining more attention worldwide as the proved oil reserves are declining and the oil price is hiking. Although many giant oil reservoirs in the world were already screened for EOR processes, the main challenges such as low sweep efficiency, costly techniques, possible formation damages, transportation of huge amounts of EOR agents to the fields especially for offshore cases, analyzing micro-scale multi-phase flow in the rock to the large scale tests and the lack of analyzing tools in traditional experimental works, hinder the proposed EOR processes. Our past experiences on using nanotechnology to the upstream cases, especially EOR processes, revealed...
Design and Realization of a Microstrip Antenna Array for Both Automotive Radar Application and 5G Communications at 78/28 GHZ Band
, M.Sc. Thesis Sharif University of Technology ; Farzaneh, Forouhar (Supervisor)
Abstract
With the advancement of automotive technology, the use of automotive radar for collision avoidance and pedestrian detection has been increasingly become universal. In this thesis, our goal is to design a dual-band radar antenna for obstacle detection and a 5G omnidirectional antenna for communication purposes in self-driving cars. We will first introduce the automotive radar and its operation. Next, the FMCW radar, which is simultaneously effective for speed, distance and direction estimation is introduced. Then we introduce the leaky wave antenna as the frequency scanning antenna. This is realized in an SIW waveguide technology. The main issue in this part is the achievement of high...
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
2014
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...
Reduction of fine migration in different pH and salinity conditions using nanofluid
, Article SPE - European Formation Damage Conference, Proceedings, EFDC ; Volume 2 , 2013 , Pages 737-743 ; 9781627486101 (ISBN) ; Pourafshary, P ; Ayatollahi, S ; Sharif University of Technology
2013
Abstract
Movement and transportation of fine particles in formations leads to clogging the pores and reduction in permeability. This type of formation damage is stronglycontingent upon water salinity and ionic conditions in the formation. The main parameters which control the particle release are the interactions and forces between particles and porous medium surfaces. Changing salinity which leads to pH alteration, affects these interactions and subsequently the fine migration process. Hence, pH and salinity variations should be considered to study and evaluate the portion of fine migration in formation damage. The principal challenge in this research therefore, is to try to change the surface...
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...
Temperature and composition effect on CO2 miscibility by interfacial tension measurement
, Article Journal of Chemical and Engineering Data ; Volume 58, Issue 5 , March , 2013 , Pages 1168-1175 ; 00219568 (ISSN) ; Escrochi, M ; Ayatollahi, S ; Sharif University of Technology
2013
Abstract
Crude oil reservoirs have different temperatures, compositions, and pressures, therefore oil recovery performance by CO2 injection varies from one case to another. Furthermore, it is predicted that lower interfacial tension between injected CO2 and reservoir fluid results in more oil recovery. In this study, we investigate the effect of temperature on the equilibrium interfacial tension between CO2 and three different oil fluids at different pressures. Also minimum miscible pressure (MMP) is measured by the vanishing interfacial tension (VIT) technique to determine the temperature effect on the CO2 miscible gas injection. The results on different pure and mixtures of hydrocarbon fluids show...
Investigation of effects of salinity, temperature, pressure, and crude oil type on the dynamic interfacial tensions
, Article Chemical Engineering Research and Design ; Volume 115 , 2016 , Pages 53-65 ; 02638762 (ISSN) ; Riazi, M ; Ayatollahi, S ; Sharif University of Technology
Institution of Chemical Engineers
2016
Abstract
The main objectives of this study are to determine the influence of crude oil type, salinity, temperature and pressure on the dynamic interfacial tension (DIFT) of crude oil based on the experiments and modeling approaches. DIFT is also modeled using dynamic adsorption models, mono-exponential decay model as well as empirical equations. The results showed that when temperature increases, unlike deionized water which inversion phase temperature was observed, the equilibrium IFT of crude oils/sea water increases due to reduction of surface excess concentration of natural surfactants at the fluid/fluid interface as a dominant mechanism
Visual investigation and modeling of asphaltene precipitation and deposition during CO2 miscible injection into oil reservoirs
,
Article
Fuel
;
Volume 160
,
2015
,
Pages 132-139
;
00162361 (ISSN)
; Dashti, H
; Ayatollahi, S
;
Sharif University of Technology
Elsevier Ltd
2015
Abstract
Abstract Miscible carbon dioxide (CO2 ) flooding has become the most commonly and favorable approach in Enhanced Oil Recovery (EOR) because of its high oil reservoir sweep efficiency and contribution to the reduction of greenhouse gas emissions. Despite this, it can significantly favor the asphaltene deposition, which leads to the wettability reversal and formation damage. A novel experimental setup was utilized to study asphaltene deposition on the model rock at reservoir condition. The evolution of asphaltene deposition was monitored by a microscope; then analyzed by image processing software to check the amount of deposited asphaltene and its size distribution at different...
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...
Study of Absorption Enhancement of CO2 by SiO2, Al2O3, CNT, and Fe3O4 Nanoparticles in Water and Amine Solutions
, Article Journal of Chemical and Engineering Data ; Volume 61, Issue 4 , 2016 , Pages 1378-1387 ; 00219568 (ISSN) ; Keshavarz, P ; Ayatollahi, S ; Sharif University of Technology
American Chemical Society
2016
Abstract
In this work, the absorption process of carbon dioxide is performed in a custom designed high pressure experimental setup in which the gas and nanofluid are in direct contact at static state in a closed vessel. The initial condition of the tests are set at 20, 30, and 40 bar and 308 K. Nanoparticles of SiO2, Al2O3, Fe3O4, and carbon nanotubes (CNTs) are dispersed in pure water to form nanofluids at concentrations of 0.02, 0.05, and 0.1 wt %. Also, CNT nanoparticle has been dispersed in methyldiethanolamine and diethanolamine aqueous solutions at the concentration of 0.02 wt %. The absorption performances of different nanofluids are compared with the base solutions and with other nanofluids...
Effect of CO2 and natural surfactant of crude oil on the dynamic interfacial tensions during carbonated water flooding: experimental and modeling investigation
, Article Journal of Petroleum Science and Engineering ; Volume 159 , 2017 , Pages 58-67 ; 09204105 (ISSN) ; Riazi, M ; Ayatollahi, S ; Sharif University of Technology
2017
Abstract
Carbonated water has been recently proposed as an enhanced oil recovery method for crude oil reservoirs. Interfacial tension (IFT) plays a crucial rule on the displacement of trapped oil ganglia in the porous media. This investigation is designed to systematically assess the dynamic interfacial tension (DIFT) of two different types of crude oils with carbonated water (CW). In addition, the measured experimental data were applied into specified models. The DIFT behavior of acidic and non-acidic crude oil samples/CW and deionized water (DW) are also compared to find the effect of dissolved carbon dioxide in water on IFT. At the next stage, DIFT of all the results were used through three...
Experimental Investigation of Acidizing in Natural Fractured Carbonates to the Optimum Injection Condition
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahabodin (Supervisor)
Abstract
In many cases, oil and gas extraction from reservoirs due to damage and permeability reduction near wellbore is lower than optimum level and reduces the flow of oil into the well. In fact, formation damage is the collapse of natural condition of reservoirs, In addition to delaying production and increasing costs, it causes early desertification of wells. Well stimulation methods are used to solve this problem and increase production. One of the most effective ways to increase the production of wells is well acidizing. In this study, the acid performance of the fractured carbonate reservoirs has been investigated. In this type of reservoirs, due to the existence of high permeable paths of the...
Effect of CO2 and crude oil type on the dynamic interfacial tension of crude oil/carbonated water at different operational conditions
, Article Journal of Petroleum Science and Engineering ; Volume 170 , 2018 , Pages 576-581 ; 09204105 (ISSN) ; Riazi, M ; Ayatollahi, S ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Concerns about climate change have persuaded the researchers to examine CO2 injection in the form of carbonated water (CW) into oil reservoir as a safe and effective CO2 storage and enhanced oil recovery process. Although interfacial tension (IFT) between crude oil and injected fluid has a vital role on the displacement of fluids in porous media, the effect of CO2 and crude oil type on the dynamic IFT of crude oil under different operational conditions is not well understood. Accordingly, this study was carried out to assess the effects of temperature, pressure, crude oil type and CO2 on the dynamic IFT of crude oil/CW. To achieve this goal, two types of crude oil were provided from southern...
Viscous fingering and its effect on areal sweep efficiency during waterflooding: an experimental study
, Article Petroleum Science ; 2018 ; 16725107 (ISSN) ; Riazi, M ; Ayatollahi, S ; Sharif University of Technology
China University of Petroleum Beijing
2018
Abstract
Viscous fingering is one of the main challenges that could reduce areal sweep efficiency during waterflooding in oil reservoirs. A series of waterflooding experiments were carried out in a Hele-Shaw cell at ambient temperature during which areal sweep efficiency was estimated and techniques to ease the fingering problem were examined. The onset and propagation of viscous fingers were monitored as a function of both injection rate and injection/production positions. Image processing techniques were utilized to quantitatively investigate the propagation of fingers. The experimental results show that, under specific conditions, increasing the number of finger branches could improve the areal...
Experimental investigation of dynamic swelling and Bond number of crude oil during carbonated water flooding; Effect of temperature and pressure
, Article Fuel ; Volume 214 , 2018 , Pages 135-143 ; 00162361 (ISSN) ; Riazi, M ; Ayatollahi, S ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The potential of crude oil swelling is dominant mechanism in the development and implementation of carbonated water (CO2 saturated water) flooding as an environmental friendly enhanced oil recovery method. In this study, the volume of crude oil drop in carbonated water (CW) was measured at temperatures of 30, 50 and 80 °C and pressures of 500, 1000, 2000 and 4000 psi to investigate the swelling behavior of crude oil during CW flooding. In addition, the variations of dynamic and equilibrium Bond number of CW/crude oil due to dissolution of CO2 in the crude oil are compared to the crude oil/water systems. It is expected that crude oil swelling decreases as temperature increases due to a...
Viscous fingering and its effect on areal sweep efficiency during waterflooding: an experimental study
, Article Petroleum Science ; Volume 16, Issue 1 , 2019 , Pages 105-116 ; 16725107 (ISSN) ; Riazi, M ; Ayatollahi, S ; Sharif University of Technology
China University of Petroleum Beijing
2019
Abstract
Viscous fingering is one of the main challenges that could reduce areal sweep efficiency during waterflooding in oil reservoirs. A series of waterflooding experiments were carried out in a Hele-Shaw cell at ambient temperature during which areal sweep efficiency was estimated and techniques to ease the fingering problem were examined. The onset and propagation of viscous fingers were monitored as a function of both injection rate and injection/production positions. Image processing techniques were utilized to quantitatively investigate the propagation of fingers. The experimental results show that, under specific conditions, increasing the number of finger branches could improve the areal...
Experimental investigation on the dominating fluid-fluid and rock-fluid interactions during low salinity water flooding in water-wet and oil-wet calcites
, Article Journal of Petroleum Science and Engineering ; Volume 204 , 2021 ; 09204105 (ISSN) ; Fatemi, M ; Ayatollahi, S ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Low salinity water flooding (LSWF) has the potential to enhance the oil recovery by affecting the fluid-fluid and rock-fluid interactions. Therefore, a systematic investigation on the effect of initial wetting state (water-wet or oil-wet) of pure calcite is conducted to study the importance of these interactions on the effectiveness of LSWF. In the case of initially water-wet cores, more oil recovery efficiency is observed for more saline water cases. To shed light on the possible involved mechanisms, dynamic IFT, dynamic contact angle (CA), oil/brine and rock/brine surfaces zeta potentials, and effluent pH are measured. It is shown that the short-term effect of IFT reduction and long-term...
Experimental and Modeling Study of Scale and Flow Geometry Effects on Carbonate Matrix Acidizing Efficiency
, Ph.D. Dissertation Sharif University of Technology ; Ayatollahi, Shahaboddin (Supervisor)
Abstract
Acidizing is one of the common methods of stimulating the well to remove formation damage and Skin factor. In carbonate reservoirs, hydrochloric acid creates permeable channels called wormholes due to the reaction with the porous medium. Previous researches have studied the effect of the main rock and fluid parameters (temperature, pressure, type and concentration of acid and rock lithology) at the core scale. However, wellbore scale will different from core scale due to the difference in the wormhole density, the flow geometry, the amount of acid leakage from wormhole wall and competition. Very limited models predict these effects for large scales. In this research, the geometry of linear...
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
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....