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heavy-oil-production
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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....
Monitoring the effect of discontinuous shales on the surfactant flooding performance in heavy oil reservoirs using 2D glass micromodels
, Article Petroleum Science and Technology ; Vol. 32, issue. 12 , Apr , 2014 , p. 1404-1417 ; ISSN: 10916466 ; Kharrat, R ; Masihi, M ; Ghazanfari, M. H ; Saidian, M ; Sharif University of Technology
Abstract
Although most heavy oil reservoirs contain discontinuous shaly structures, there is a lack of fundamental understanding how the shaly structures affect the oil recovery efficiency, especially during surfactant flooding to heavy oils. Here, an experimental study was conducted to examine the effect of discontinuous shales on performance of surfactant flooding by introducing heterogeneities to represent streaks of shale in five-spot glass micromodels. Results show that oil recovery in presence of shale streak is lower than in its absence. Based on the authors' observations, the presence of flow barriers causes premature breakthrough of injected fluids and also an unstable displacement front. As...
Effect of small scale flow barriers heterogeneities and connate water on displacement efficiency of polymer floods to heavy oil reservoirs
, Article Canadian Journal of Chemical Engineering ; Vol. 91, issue. 10 , October , 2013 , p. 1729-1740 ; ISSN: 00084034 ; Ghazanfari, M. H ; Masihi, M ; Vossoughi, S ; Sharif University Of Technology
Abstract
This work concerns a fundamental understanding of how heterogeneities induced by flow barriers and connate water affect the displacement efficiency of polymer floods, which has rarely been studied in the available literature. Here, a series of water/polymer injection experiments to heavy oil performed on five-spot glass micromodels containing randomly distributed shale structures is presented. It has been found that macroscopic efficiency of polymer flooding majorly depends on flow barriers distribution/configuration; shale content and geometrical characteristics; presence of connate water and wettability of medium. Microscopic pictures revealed that the main parts of connate water were...
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...
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...
Experimental study of miscible displacement with hydrocarbon solvent in shaly heavy oil reservoirs using five-spot micromodels: The role of shale geometrical characteristics
, Article Journal of Porous Media ; Vol. 15, issue. 5 , 2012 , p. 415-427 ; ISSN: 1091028X ; Ghazanfari, M. H ; Masihi, M ; Kharrat, R ; Sharif University of Technology
Abstract
Most of the heavy oil reservoirs contain discontinuous shale which affects fluid flow through porous media as well as recovery efficiency during enhanced oil recovery processes. However, the role of shale geometrical characteristics (including orientation, length, discontinuity, and spacing of the shale) on oil recovery remains a topic of debate in the literature, especially during miscible injection of heavy oils and five-spot systems. Here, a series of hydrocarbon solvent injection tests have been performed on various five-spot glass micromodels containing barriers which are initially saturated with heavy oil under fixed flow rate conditions. Oil recoveries as a function of pore volumes of...
The semi-analytical modeling and simulation of the VAPEX process of ""Kuh-e-Mond"" heavy oil reservoir
, Article Petroleum Science and Technology ; Vol. 29, issue. 5 , Oct , 2009 , p. 535-548 ; ISSN: 10916466 ; Masihi, M ; Kharrat, R ; Sharif University of Technology
Abstract
The vapor extraction process (or VAPEX) uses vaporized solvents injected into a horizontal well to form a vapor chamber within the reservoir. Vapor dissolves in the oil and enhances the oil production by decreasing the oil viscosity in heavy oil reservoirs. To evaluate the process we conduct a simulation study on an Iranian heavy oil reservoir called Kuh-e-Mond. In addition, a semi-analytical investigation of the VAPEX process has been performed. The idea is to perform VAPEX simulation for a laboratory model and find a methodology to compare the results of the simulator with the semi-analytical Butler's model. In particular, a semi-analytical dimensionless correlation for production rate...
Experimental and simulation studies of the effect of vertical permeability barriers on oil recovery efficiency during solvent injection processes
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Vol. 33, issue. 20 , Nov , 2009 , p. 1889-1900 ; ISSN: 15567036 ; Farzaneh, S. A ; Kharrat, R ; Ghazanfari, M. H ; Masihi, M ; Sharif University of Technology
Abstract
Almost all of the heavy oil reservoirs contain discontinuous permeability barriers (shales) with different structures. However, the effect of shaly layer geometrical characteristics including: spacing from wells, discontinuity, orientation, shaly layers' spacing and length, and heterogeneous distribution on oil recovery factor in the presence of gravity force are not well understood. In this work, a series of solvent injection experiments were conducted on various vertical one-quarter five-spot glass micromodels, containing barriers, which were initially saturated with a heavy oil sample. The oil recovery was measured by analysis of the pictures provided continuously during the injection...
A study of enhanced heavy oil recovery by two well cyclical steam assisted gravity drainage (TWC-SAGD) in conventional and fractured reservoirs
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Vol. 36, issue. 10 , Dec , 2014 , pp. 1065-1076 ; ISSN: 15567036 ; Bolouri, S. H ; Sharif University of Technology
Abstract
Steam-assisted gravity drainage is one of the most promising strategies to develop huge heavy oil and bitumen accumulations. Like the other thermal processes, this method aims at reducing oil viscosity by increasing the temperature. But in an economical point of view, it requires a great volume of steam for injection. Moreover, early breakthrough of steam and high steam-oil ratio makes it uneconomical, especially in long production time. In this study, a new method, two wells cyclical steam-assisted gravity drainage is compared with a conventional steam-assisted gravity drainage process. Well configuration in two wells cyclical steam-assisted gravity drainage is the same as the...
Enhanced heavy oil recovery in sandstone cores using TiO2 nanofluids
, Article Energy and Fuels ; Vol. 28, issue. 1 , 2014 , pp. 423-430 ; ISSN: 08870624 ; Ahadian, M. M ; Taghikhani, V ; Ghazanfari, M. H ; Sharif University of Technology
Abstract
Anatase and amorphous TiO2 nanoparticles were used to improve recovery of heavy oil from sandstone cores. Before performing core floods, the stability of nanoparticles at different salinities was tested using ζ potential and ultraviolet-visible (UV-vis) methods. While water recovered only 49% of the oil in the core flood experiments, 0.01% anatase structure solution recovered 80% of the oil after injecting two pore volumes at optimum conditions. To understand the mechanism responsible for improved recovery, contact angle measurements were performed on the rock surface before and after treatment with the nanoparticle solution. Contact angle measurements showed that the rock wettability...
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...
Effects of asphaltene content and temperature on viscosity of Iranian heavy crude oil: Experimental and modeling study
, Article Energy and Fuels ; Volume 27, Issue 12 , 2013 , Pages 7217-7232 ; ISSN: 08870624 ; Shojaei, M. J ; Ahmad Ramazani, S. A ; Sharif University of Technology
2013
Abstract
Heavy and extra heavy crude oils usually have a high weight percentage of asphaltene, which could induce many problems during production to refining processes. Also, asphaltene has the main role on the high viscosity of the heavy and extra heavy crude oils. In this paper, the effects of asphaltene characteristics on the crude oil rheological properties have been experimentally and theoretically investigated using different classes of the suspension models. For experimental investigation, the asphaltene was first precipitated from the original heavy crude oil and then 10 well-defined reconstituted heavy oil samples are made by dispersing the asphaltene into the maltene (i.e., deasphalted...
Application of fast-SAGD in naturally fractured heavy oil reservoirs: A case study
, Article SPE Middle East Oil and Gas Show and Conference, MEOS, Proceedings, Manama ; Volume 3 , March , 2013 , Pages 1946-1953 ; 9781627482851 (ISBN) ; Hashemi Kiasari, H ; Alizadeh, N ; Mighani, S ; Kamari, A ; Baker Hughes ; Sharif University of Technology
2013
Abstract
Steam injection process has been considered for a long time as an effective method to exploit heavy oil resources. Over the last decades, Steam Assisted Gravity Drainage (SAGD) has been proved as one of the best steam injection methods for recovery of unconventional oil resources. Recently, Fast-SAGD, a modification of the SAGD process, makes use of additional single horizontal wells alongside the SAGD well pair to expand the steam chamber laterally. This method uses fewer wells and reduces the operational cost compared to a SAGD operation requiring paired parallel wells one above the other. The efficiency of this new method in naturally fractured reservoir is not well understood....
Experimental and numerical investigation of polymer flooding in fractured heavy oil five-spot systems
, Article Journal of Petroleum Science and Engineering ; Volume 108 , 2013 , Pages 370-382 ; 09204105 (ISSN) ; Ghazanfari, M. H ; Masihi, M ; Rashtchian, D ; Sharif University of Technology
2013
Abstract
Microscopic and macroscopic displacements of polymer flooding to heavy oil at various levels of salinity and connate water saturation have been investigated. Both oil-wet and water-wet conditions in fractured five-spot micromodel systems, initially saturated with the heavy crude oil are utilized. The primary contribution is to examine the role of salinity, wettability, connate water, and fracture geometry in the recovery efficiency of the system. The microscopic results revealed that the increase in the connate water saturation decreases the oil recovery, independent of the wettability conditions. Moreover, the increase in salinity of the injected fluids lowers the recovery efficiency due to...
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...
Comparing the performance and recovery mechanisms for steam flooding in heavy and light oil reservoirs
, Article Society of Petroleum Engineers- SPE Heavy Oil Conference ; Volume 1 , 2012 , Pages 28-36 ; 9781622761111 (ISBN) ; Ayatollahi, S ; Shabaninejad, M ; Sharif University of Technology
SPE
2012
Abstract
The concern over fossil energy shortage for the next decade leads to the extensive research activities in the area of enhanced oil recovery. Steam injection as one of well known EOR process has been used for about five decades to improve the oil production rate and recovery efficiency. Steam flooding is applied to heavy and extra-heavy oil reservoirs; however it could be used in light oil reservoirs in which water injection do not work effectively. Regardless of different performances, this method is an efficient EOR process for both heavy and light oil reservoirs. In this work, two separate numerical models were prepared to investigate steam flooding performance for the recovery of light...
Macroscopic recovery mechanisms of in-situ combustion process in heavy oil fractured systems: Effect of fractures geometrical properties and operational parameters
, Article Society of Petroleum Engineers - SPE EOR Conference at Oil and Gas West Asia 2012, OGWA - EOR: Building Towards Sustainable Growth ; Volume 2 , 2012 , Pages 593-617 ; 9781622760473 (ISBN) ; Kharrat, R ; Vossoughi, S ; Ghotbi, C ; Sharif University of Technology
SPE
2012
Abstract
The In-Situ Combustion (ISC) as a thermal EOR process has been studied deeply in heavy oil reservoirs and is a promising method for certain non-fractured sandstones. However, its feasibility in fractured carbonates remained questionable. The aim of the present work was to understand the recovery mechanisms of ISC in fractured models and to evaluate the effect of fractures geometrical properties such as orientation, density, location and networking on the ISC recovery performance. Combustion parameters of a fractured low permeable carbonate heavy oil reservoir in Middle East called KEM; applied to simulation study. Simulator has been validated with KEM combustion tube experimental data and...