Documents disponibles écrits par cet auteur

Enhanced mass transfer of CO2 into water / R. Farajzadeh in Industrial & engineering chemistry research, Vol. 48 N° 13 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6423–6431 Titre : Enhanced mass transfer of CO2 into water : experiment and modeling Type de document : texte imprimé Auteurs : R. Farajzadeh, Auteur ; P. L. J. Zitha, Auteur ; J. Bruining, Auteur Année de publication : 2009 Article en page(s) : pp. 6423–6431 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : CO2  Sub-surface  water  Mass  transfer Résumé : Concern over global warming has increased interest in quantification of the dissolution of CO2 in (sub-)surface water. The mechanisms of the mass transfer of CO2 in aquifers and of transfer to surface water have many common features. The advantage of experiments using bulk water is that the underlying assumptions to the quantify mass-transfer rate can be validated. Dissolution of CO2 into water (or oil) increases the density of the liquid phase. This density change destabilizes the interface and enhances the transfer rate across the interface by natural convection. This paper describes a series of experiments performed in a cylindrical PVT-cell at a pressure range of pi = 10−50 bar, where a fixed volume of CO2 gas was brought into contact with a column of distilled water. The transfer rate is inferred by following the gas pressure history. The results show that the mass-transfer rate across the interface is much faster than that predicted by Fickian diffusion and increases with increasing initial gas pressure. The theoretical interpretation of the observed effects is based on diffusion and natural convection phenomena. The CO2 concentration at the interface is estimated from the gas pressure using Henry’s solubility law, in which the coefficient varies with both pressure and temperature. Good agreement between the experiments and the theoretical results has been obtained. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801521u [article] Enhanced mass transfer of CO2 into water : experiment and modeling [texte imprimé] / R. Farajzadeh, Auteur ; P. L. J. Zitha, Auteur ; J. Bruining, Auteur . - 2009 . - pp. 6423–6431. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6423–6431 Mots-clés : CO2  Sub-surface  water  Mass  transfer Résumé : Concern over global warming has increased interest in quantification of the dissolution of CO2 in (sub-)surface water. The mechanisms of the mass transfer of CO2 in aquifers and of transfer to surface water have many common features. The advantage of experiments using bulk water is that the underlying assumptions to the quantify mass-transfer rate can be validated. Dissolution of CO2 into water (or oil) increases the density of the liquid phase. This density change destabilizes the interface and enhances the transfer rate across the interface by natural convection. This paper describes a series of experiments performed in a cylindrical PVT-cell at a pressure range of pi = 10−50 bar, where a fixed volume of CO2 gas was brought into contact with a column of distilled water. The transfer rate is inferred by following the gas pressure history. The results show that the mass-transfer rate across the interface is much faster than that predicted by Fickian diffusion and increases with increasing initial gas pressure. The theoretical interpretation of the observed effects is based on diffusion and natural convection phenomena. The CO2 concentration at the interface is estimated from the gas pressure using Henry’s solubility law, in which the coefficient varies with both pressure and temperature. Good agreement between the experiments and the theoretical results has been obtained. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801521u

Gravity-enhanced transfer between fracture and matrix in solvent-based enhanced oil recovery / S. Kahrobaei in Industrial & engineering chemistry research, Vol. 51 N° 44 (Novembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 44 (Novembre 2012) . - pp. 14555–14565 Titre : Gravity-enhanced transfer between fracture and matrix in solvent-based enhanced oil recovery Type de document : texte imprimé Auteurs : S. Kahrobaei, Auteur ; R. Farajzadeh, Auteur ; V.S. Suicmez, Auteur Année de publication : 2013 Article en page(s) : pp. 14555–14565 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Solvent  Oil Résumé : Solvent injection has been considered as an efficient method for enhancing oil recovery from fractured reservoirs. The success of this method therefore depends on the degree of enhancement of the mass exchange rate between the solvent residing in the fracture and the oil residing in the matrix. If the mass transfer would be solely based on diffusion, oil recovery would be unacceptably slow. A series of soak experiments have been conducted to investigate the mass transfer rate between the fracture and the matrix. In a soak experiment, a porous medium containing oil is immersed in an open space containing the solvent to simulate the matrix and the fracture, respectively. We use a CT scanner to visualize the process. The experimental data are compared with a simulation model that takes diffusive and gravitational forces into account. We find that the initial stage of all experiments can be described by a diffusion-based model with an enhanced “effective diffusion coefficient”. In the second stage enhancement of the transfer rate occurs due to the natural convection of solvent in the fracture. The experiments are quantitatively modeled by numerical simulations. We find that transfer rates depend on the properties of the rock permeability, the viscosity and the density of solvent and oil. The gravity enhanced transfer is quantified by comparison of experimental and simulated results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3014499 [article] Gravity-enhanced transfer between fracture and matrix in solvent-based enhanced oil recovery [texte imprimé] / S. Kahrobaei, Auteur ; R. Farajzadeh, Auteur ; V.S. Suicmez, Auteur . - 2013 . - pp. 14555–14565. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 44 (Novembre 2012) . - pp. 14555–14565 Mots-clés : Solvent  Oil Résumé : Solvent injection has been considered as an efficient method for enhancing oil recovery from fractured reservoirs. The success of this method therefore depends on the degree of enhancement of the mass exchange rate between the solvent residing in the fracture and the oil residing in the matrix. If the mass transfer would be solely based on diffusion, oil recovery would be unacceptably slow. A series of soak experiments have been conducted to investigate the mass transfer rate between the fracture and the matrix. In a soak experiment, a porous medium containing oil is immersed in an open space containing the solvent to simulate the matrix and the fracture, respectively. We use a CT scanner to visualize the process. The experimental data are compared with a simulation model that takes diffusive and gravitational forces into account. We find that the initial stage of all experiments can be described by a diffusion-based model with an enhanced “effective diffusion coefficient”. In the second stage enhancement of the transfer rate occurs due to the natural convection of solvent in the fracture. The experiments are quantitatively modeled by numerical simulations. We find that transfer rates depend on the properties of the rock permeability, the viscosity and the density of solvent and oil. The gravity enhanced transfer is quantified by comparison of experimental and simulated results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3014499

Investigation of immiscible and miscible foam for enhancing oil recovery / R. Farajzadeh in Industrial & engineering chemistry research, Vol. 49 N° 4 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1910–1919 Titre : Investigation of immiscible and miscible foam for enhancing oil recovery Type de document : texte imprimé Auteurs : R. Farajzadeh, Auteur ; Andrianov, A., Auteur ; P. L. J. Zitha, Auteur Année de publication : 2010 Article en page(s) : pp 1910–1919 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Immiscible  miscible  foam  Oil  recovery. Résumé : We report the study of flow of CO2 and N2 foam in natural sandstone cores containing oil with the aid of X-ray computed tomography. The study is relevant for enhanced oil recovery (EOR). The cores were partially saturated with oil and brine (half top) and brine only (half bottom) to mimic the water−oil transition occurring in oil reservoirs. The CO2 was used either under subcritical conditions (P = 1 bar) or under supercritical (immiscible (P = 90 bar) and miscible (P = 137 bar)) conditions, whereas N2 remained subcritical. Prior to gas injection the cores were flooded with several pore volumes of water. In a typical foam experiment water flooding was followed by the injection of 1−2 pore volumes of a surfactant solution with alpha olefin sulfonate (AOS) as the foaming agent. We visually show how foam propagates in a porous medium containing oil. At low-pressure experiments (P = 1 bar) in the case of N2, weak foam could be formed in the oil-saturated part. Diffused oil bank is formed ahead of the foam front, which results in additional oil recovery, compared to pure gas injection. CO2 hardly foams in the oil-bearing part of the core, most likely due to its higher solubility. Above the critical point (P = 90 bar), CO2 injection following the slug of surfactant reduces its mobility when there is no oil. Nevertheless, when the foam front meets the oil, the interface between gas and liquid disappears. The presence of the surfactant (when foaming supercritical CO2) did not affect the oil recovery and pressure profile, indicating the detrimental effect of oil on foam stability in the medium. However, at miscible conditions (P = 137 bar), injection of surfactant prior to CO2 injection significantly increases the oil recovery. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901109d [article] Investigation of immiscible and miscible foam for enhancing oil recovery [texte imprimé] / R. Farajzadeh, Auteur ; Andrianov, A., Auteur ; P. L. J. Zitha, Auteur . - 2010 . - pp 1910–1919. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1910–1919 Mots-clés : Immiscible  miscible  foam  Oil  recovery. Résumé : We report the study of flow of CO2 and N2 foam in natural sandstone cores containing oil with the aid of X-ray computed tomography. The study is relevant for enhanced oil recovery (EOR). The cores were partially saturated with oil and brine (half top) and brine only (half bottom) to mimic the water−oil transition occurring in oil reservoirs. The CO2 was used either under subcritical conditions (P = 1 bar) or under supercritical (immiscible (P = 90 bar) and miscible (P = 137 bar)) conditions, whereas N2 remained subcritical. Prior to gas injection the cores were flooded with several pore volumes of water. In a typical foam experiment water flooding was followed by the injection of 1−2 pore volumes of a surfactant solution with alpha olefin sulfonate (AOS) as the foaming agent. We visually show how foam propagates in a porous medium containing oil. At low-pressure experiments (P = 1 bar) in the case of N2, weak foam could be formed in the oil-saturated part. Diffused oil bank is formed ahead of the foam front, which results in additional oil recovery, compared to pure gas injection. CO2 hardly foams in the oil-bearing part of the core, most likely due to its higher solubility. Above the critical point (P = 90 bar), CO2 injection following the slug of surfactant reduces its mobility when there is no oil. Nevertheless, when the foam front meets the oil, the interface between gas and liquid disappears. The presence of the surfactant (when foaming supercritical CO2) did not affect the oil recovery and pressure profile, indicating the detrimental effect of oil on foam stability in the medium. However, at miscible conditions (P = 137 bar), injection of surfactant prior to CO2 injection significantly increases the oil recovery. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901109d