Documents disponibles écrits par cet auteur

Maximum drag reduction asymptote of polymeric fluid flow in coiled tubing / Subhash N. Shah in Transactions of the ASME . Journal of fluids engineering, Vol. 131 N° 1 (Janvier 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 131 N° 1 (Janvier 2009) . - 09 p. Titre : Maximum drag reduction asymptote of polymeric fluid flow in coiled tubing Type de document : texte imprimé Auteurs : Subhash N. Shah, Auteur ; Yunxu Zhou, Auteur Année de publication : 2009 Article en page(s) : 09 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : drag  reduction;  coiled  tubing;  polymer  fluids Résumé : This study experimentally investigates the drag reduction characteristics of the most commonly used polymer fluids in coiled tubing applications. The flow loop employed consists of 12.7mm straight and coiled tubing sections. The curvature ratio (a∕R, where a and R are the radii of the tubing and the reel drum, respectively) investigated is from 0.01 to 0.076, which covers the typical curvature ratio range encountered in the oil and gas industry applications. Fluids tested include xanthan gum, guar gum, and hydroxypropyl guar at various polymer concentrations. It is found that the drag reduction in coiled tubing is significantly lower than that in straight tubing, probably due to the effect of secondary flow in curved geometry. The onset of drag reduction is also found to be delayed as the curvature ratio was increased. A correlation for the maximum drag reduction (MDR) asymptote in coiled tubing is developed. When the curvature ratio is set to zero, the new correlation reduces to the well-known Virk’s MDR asymptote for dilute polymer solutions in straight pipes. A new drag reduction envelope is proposed for the analysis of drag reduction behavior of polymeric fluids in coiled tubing. Application of the new drag reduction envelope is also discussed. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Maximum drag reduction asymptote of polymeric fluid flow in coiled tubing [texte imprimé] / Subhash N. Shah, Auteur ; Yunxu Zhou, Auteur . - 2009 . - 09 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 131 N° 1 (Janvier 2009) . - 09 p. Mots-clés : drag  reduction;  coiled  tubing;  polymer  fluids Résumé : This study experimentally investigates the drag reduction characteristics of the most commonly used polymer fluids in coiled tubing applications. The flow loop employed consists of 12.7mm straight and coiled tubing sections. The curvature ratio (a∕R, where a and R are the radii of the tubing and the reel drum, respectively) investigated is from 0.01 to 0.076, which covers the typical curvature ratio range encountered in the oil and gas industry applications. Fluids tested include xanthan gum, guar gum, and hydroxypropyl guar at various polymer concentrations. It is found that the drag reduction in coiled tubing is significantly lower than that in straight tubing, probably due to the effect of secondary flow in curved geometry. The onset of drag reduction is also found to be delayed as the curvature ratio was increased. A correlation for the maximum drag reduction (MDR) asymptote in coiled tubing is developed. When the curvature ratio is set to zero, the new correlation reduces to the well-known Virk’s MDR asymptote for dilute polymer solutions in straight pipes. A new drag reduction envelope is proposed for the analysis of drag reduction behavior of polymeric fluids in coiled tubing. Application of the new drag reduction envelope is also discussed. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

Rheological and hydraulic properties of welan um fluids in straight and coiled tubings / Adedeji Asubiaro in Transactions of the ASME . Journal of fluids engineering, Vol. 130 N° 8 (Août 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 130 N° 8 (Août 2008) . - 16 p. Titre : Rheological and hydraulic properties of welan um fluids in straight and coiled tubings Type de document : texte imprimé Auteurs : Adedeji Asubiaro, Auteur ; Subhash N. Shah, Auteur Année de publication : 2009 Article en page(s) : 16 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Flow  (dynamics)  ;  friction;  fluids;  tubing Résumé : This study involves experimental investigation of the hydraulic characteristics of aqueous based welan gum fluids of concentrations 1.4kg∕m3, 2.9kg∕m3, 5.7kg∕m3, and 8.6kg∕m3 in both straight and coiled tubings at 21°C, with particular emphasis on the effect of polymer concentration and coiled tubing curvature ratio. The flow loop available at the Well Construction Technology Center of the University of Oklahoma, consisting of 1.27cm straight and coiled tubings (with curvature ratios of 0.01, 0.019, and 0.031), was utilized. It was observed that for all welan gum fluids investigated, friction losses in coiled tubing were significantly higher than those in straight tubing. In addition, increasing coiled tubing curvature ratio brings about higher friction loss for all fluids investigated. Rheological data for these fluids were obtained using a Model 35 Fann viscometer. Friction pressure data gathered from flow experiments are analyzed and correlations for friction pressure loss prediction of welan gum fluids have been developed for both straight and coiled tubings. These correlations, which represent the industry’s first attempt in the fundamental investigation of friction loss prediction of welan gum fluids, are found to provide good accuracy when compared to the experimental data. Flow behavior of welan gum fluids is compared with 4.9kg∕m3 guar fluid. It is found that in both straight and coiled tubings, the guar fluid exhibited higher drag reduction when compared to the welan gum fluids investigated in this study. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27329 [...] [article] Rheological and hydraulic properties of welan um fluids in straight and coiled tubings [texte imprimé] / Adedeji Asubiaro, Auteur ; Subhash N. Shah, Auteur . - 2009 . - 16 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 130 N° 8 (Août 2008) . - 16 p. Mots-clés : Flow  (dynamics)  ;  friction;  fluids;  tubing Résumé : This study involves experimental investigation of the hydraulic characteristics of aqueous based welan gum fluids of concentrations 1.4kg∕m3, 2.9kg∕m3, 5.7kg∕m3, and 8.6kg∕m3 in both straight and coiled tubings at 21°C, with particular emphasis on the effect of polymer concentration and coiled tubing curvature ratio. The flow loop available at the Well Construction Technology Center of the University of Oklahoma, consisting of 1.27cm straight and coiled tubings (with curvature ratios of 0.01, 0.019, and 0.031), was utilized. It was observed that for all welan gum fluids investigated, friction losses in coiled tubing were significantly higher than those in straight tubing. In addition, increasing coiled tubing curvature ratio brings about higher friction loss for all fluids investigated. Rheological data for these fluids were obtained using a Model 35 Fann viscometer. Friction pressure data gathered from flow experiments are analyzed and correlations for friction pressure loss prediction of welan gum fluids have been developed for both straight and coiled tubings. These correlations, which represent the industry’s first attempt in the fundamental investigation of friction loss prediction of welan gum fluids, are found to provide good accuracy when compared to the experimental data. Flow behavior of welan gum fluids is compared with 4.9kg∕m3 guar fluid. It is found that in both straight and coiled tubings, the guar fluid exhibited higher drag reduction when compared to the welan gum fluids investigated in this study. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27329 [...]

Scale-up correlation for the flow of surfactant-based fluids in circular coiled pipes / Ahmed H. Ahmed Kamel in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 8 (Août 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 8 (Août 2010) . - 12 p. Titre : Scale-up correlation for the flow of surfactant-based fluids in circular coiled pipes Type de document : texte imprimé Auteurs : Ahmed H. Ahmed Kamel, Auteur ; Subhash N. Shah, Auteur Année de publication : 2010 Article en page(s) : 12 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : flow  (dynamics);  friction;  fluids;  tubing;  pipes;  surfactants Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This study involves experimental investigation on the flow properties of aqueous surfactant-based (SB) fluids in small and large-scale coiled tubing. It aims at understanding the viscoelastic properties and its effect on the flow behavior of SB fluids in coiled tubing. In spite of SB fluids wide use as friction reducer and/or fracturing fluid in the oil and gas industry, the flow data in large pipe sizes as well as coiled tubing are very scarce. Majority of the available flow data are gathered in straight pipes with small sizes. The scale-up of small-scale flow data is questionable due to the pronounced diameter effect. Furthermore, previous studies have correlated flow behavior of these fluids only through simple power-law model parameters. Limited work with polymeric fluids has been reported that includes fluid elasticity in scale-up procedure and it is nonexistent for highly elastic SB fluids. In this study, the properties of widely used Aromox APA-T, a highly active surfactant used as gelling agent in aqueous and brine base fluids, are thoroughly investigated. Rheological measurements are conducted using Bohlin rheometer for SB fluid concentration of 1.5 vol %, 2 vol %, 3 vol %, and 4 vol %. Flow data are gathered using 1.27 cm, 3.81 cm, 6.03 cm, and 7.30 cm OD coiled tubing with various curvature ratios. This study presents the first attempt to investigate the flow behavior SB fluids in large-scale coiled tubing. The results show that SB fluids exhibit non-Newtonian pseudoplastic behavior. Elastic and viscous properties of SB fluids are very sensitive to surfactant concentration. Friction losses in coiled tubing are significantly higher than those in straight pipes due to secondary flow effect. Increasing curvature ratio yields higher friction pressure loss. Also, small-scale data correlations using only simple power-law model fluid rheological parameters lead to erroneous results when scaled-up to large pipe sizes. New technique, based on the modified Deborah number, which includes fluid elasticity and pipe shear effect, has been developed to correlate data from the small laboratory-scale tubing and large field-scale pipes. Correlation to predict Fanning friction factor of SB fluids in coiled tubing as a function of Deborah number and fluid flow behavior index is presented. Correlation is validated by comparing predictions with the experimental data. It is shown that the new correlation accurately predicts friction factor of SB fluids and thus alleviates the scale-up issue. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Scale-up correlation for the flow of surfactant-based fluids in circular coiled pipes [texte imprimé] / Ahmed H. Ahmed Kamel, Auteur ; Subhash N. Shah, Auteur . - 2010 . - 12 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 8 (Août 2010) . - 12 p. Mots-clés : flow  (dynamics);  friction;  fluids;  tubing;  pipes;  surfactants Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This study involves experimental investigation on the flow properties of aqueous surfactant-based (SB) fluids in small and large-scale coiled tubing. It aims at understanding the viscoelastic properties and its effect on the flow behavior of SB fluids in coiled tubing. In spite of SB fluids wide use as friction reducer and/or fracturing fluid in the oil and gas industry, the flow data in large pipe sizes as well as coiled tubing are very scarce. Majority of the available flow data are gathered in straight pipes with small sizes. The scale-up of small-scale flow data is questionable due to the pronounced diameter effect. Furthermore, previous studies have correlated flow behavior of these fluids only through simple power-law model parameters. Limited work with polymeric fluids has been reported that includes fluid elasticity in scale-up procedure and it is nonexistent for highly elastic SB fluids. In this study, the properties of widely used Aromox APA-T, a highly active surfactant used as gelling agent in aqueous and brine base fluids, are thoroughly investigated. Rheological measurements are conducted using Bohlin rheometer for SB fluid concentration of 1.5 vol %, 2 vol %, 3 vol %, and 4 vol %. Flow data are gathered using 1.27 cm, 3.81 cm, 6.03 cm, and 7.30 cm OD coiled tubing with various curvature ratios. This study presents the first attempt to investigate the flow behavior SB fluids in large-scale coiled tubing. The results show that SB fluids exhibit non-Newtonian pseudoplastic behavior. Elastic and viscous properties of SB fluids are very sensitive to surfactant concentration. Friction losses in coiled tubing are significantly higher than those in straight pipes due to secondary flow effect. Increasing curvature ratio yields higher friction pressure loss. Also, small-scale data correlations using only simple power-law model fluid rheological parameters lead to erroneous results when scaled-up to large pipe sizes. New technique, based on the modified Deborah number, which includes fluid elasticity and pipe shear effect, has been developed to correlate data from the small laboratory-scale tubing and large field-scale pipes. Correlation to predict Fanning friction factor of SB fluids in coiled tubing as a function of Deborah number and fluid flow behavior index is presented. Correlation is validated by comparing predictions with the experimental data. It is shown that the new correlation accurately predicts friction factor of SB fluids and thus alleviates the scale-up issue. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]