A Comprehensive Mechanistic Model for Upward Two-Phase Flow in Wellbores

Ansari, A.M.; Sylvester, N. D.; Sarica, Cem; Shoham, Ovadia; Brill, J.P.

doi:10.2118/20630-pa

“…For this reason, over the past decades, efforts have been directed to the development of phenomenological or mechanistic correlations, i.e., correlations in which fundamental laws are used to model the most important flow phenomena and less empiricism is required [3,8].…”

Section: Pressure-gradient Correlationsmentioning

confidence: 99%

“…Although greater accuracy is expected when using a theoretical correlation instead of an empirical one, selecting a mechanistic method for use in design calculations is not a trivial task, specially when it comes to refining or petrochemical processes, for some of these methods only apply to certain pipe inclinations [8] while others [3] have not been validated enough to persuade engineers and companies into updating long-experienced design practices. It follows that empirical methods still enjoy widespread use in industry and also for comparison purposes in the development of new predictive techniques [9][10][11].…”

Section: Pressure-gradient Correlationsmentioning

confidence: 99%

Two-Phase Flow in Pipes: Numerical Improvements and Qualitative Analysis for a Refining Process

Teixeira

¹

,

Secchi

²

,

Biscaia

³

2014

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

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-Two-phase flow in pipes occurs frequently in refineries, oil and gas production facilities and petrochemical units. The accurate design of such processing plants requires that numerical algorithms be combined with suitable models for predicting expected pressure drops. In performing such calculations, pressure gradients may be obtained from empirical correlations such as Beggs and Brill, and they must be integrated over the total length of the pipe segment, simultaneously with the enthalpy-gradient equation when the temperature profile is unknown. This paper proposes that the set of differential and algebraic equations involved should be solved as a Differential Algebraic Equations (DAE) System, which poses a more CPU-efficient alternative to the "marching algorithm" employed by most related work. Demonstrating the use of specific regularization functions in preventing convergence failure in calculations due to discontinuities inherent to such empirical correlations is also a key feature of this study. The developed numerical techniques are then employed to examine the sensitivity to heat-transfer parameters of the results obtained for a typical refinery two-phase flow design problem.Re´sume´-É coulements diphasiques dans les conduites : ame´liorations nume´riques et analyse qualitative pour un proce´de´de raffinage -Les e´coulements diphasiques apparaissent fre´quemment dans les conduites des raffineries, des installations de production de pe´trole et de gaz et des unite´s pe´trochimiques. La conception pre´cise de telles unite´s requie`re l'inte´gration d'algorithmes nume´riques dans des mode`les adapte´s, afin de pre´dire les baisses de pression. Dans le cadre de tels calculs, les gradients de pression peuvent eˆtre obtenus a`partir de corre´lations empiriques, telles que celles de Beggs et Brill, et doivent eˆtre inte´gre´s sur la longueur totale du segment de la conduite, en utilisant simultane´ment l'e´quation du gradient d'enthalpie lorsque le profil de tempe´rature n'est pas connu. Cet article propose que les syste`mes d'e´quations diffe´rentielles et alge´briques en question soient re´solus sous forme d'un syste`me d'e´quations diffe´rentielles alge´briques (DAE, Differential Algebraic Equations) offrant une alternative e´conome en temps calcul (CPU) aux algorithmes de type « marching algorithm » utilise´dans la plupart des travaux connexes. Nous de´montrons aussi que l'utilisation de fonctions de re´gularisation spe´cifiques permet d'e´viter les erreurs de convergence dans les calculs, imputables aux discontinuite´s inhe´rentes a`de telles corre´lations empiriques. Les techniques nume´riques de´veloppe´es sont alors utilise´es pour examiner la sensibilite´des re´sultats obtenus aux parame`tres de transfert de chaleur pour un proble`me typique de conception d'e´coulement diphasique dans une raffinerie.

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“…Ansari [4] and Sylvester built a model to calculate a deliverability curve, pressure gradient and flux rate by Geoflow; the discontinuous pressure gradient and deliverability curve could be obtained by the Ansari Model, while the Drift Flux Model could achieve suitable results for geothermal wells [5]. Li [6] established the formation fracture pressure model with consideration of thermal stress subjected to heat transfer in the high temperature geothermal well.…”

Section: Introductionmentioning

confidence: 99%

Equivalent Circulation Density Analysis of Geothermal Well by Coupling Temperature

Zheng

¹

,

Duan

²

,

Yan

³

et al. 2017

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Abstract:The accurate control of the wellbore pressure not only prevents lost circulation/blowout and fracturing formation by managing the density of the drilling fluid, but also improves productivity by mitigating reservoir damage. Calculating the geothermal pressure of a geothermal well by constant parameters would easily bring big errors, as the changes of physical, rheological and thermal properties of drilling fluids with temperature are neglected. This paper researched the wellbore pressure coupling by calculating the temperature distribution with the existing model, fitting the rule of density of the drilling fluid with the temperature and establishing mathematical models to simulate the wellbore pressures, which are expressed as the variation of Equivalent Circulating Density (ECD) under different conditions. With this method, the temperature and ECDs in the wellbore of the first medium-deep geothermal well, ZK212 Yangyi Geothermal Field in Tibet, were determined, and the sensitivity analysis was simulated by assumed parameters, i.e., the circulating time, flow rate, geothermal gradient, diameters of the wellbore, rheological models and regimes. The results indicated that the geothermal gradient and flow rate were the most influential parameters on the temperature and ECD distribution, and additives added in the drilling fluid should be added carefully as they change the properties of the drilling fluid and induce the redistribution of temperature. To ensure the safe drilling and velocity of pipes tripping into the hole, the depth and diameter of the wellbore are considered to control the surge pressure.

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“…Ansari [4] and Drift built a model to calculate a deliverability curve, pressure gradient and flux rate by Geoflow; the discontinuous pressure gradient and deliverability curve could be obtained by the Ansari Model, while the Drift Flux Model could achieve suitable results for geothermal wells [5]. Li [6] established the formation fracture pressure model with consideration of thermal stress subjected to heat transfer in the high temperature geothermal well.…”

Section: Introductionmentioning

confidence: 99%

Equivalent Circulation Density Analysis of Geothermal Well by Coupling Temperature

Zheng¹,

Duan²,

Yan³

et al. 2017

Preprint

1

0

View full text Add to dashboard Cite

Abstract:The accurate control of the wellbore pressure not only prevents lost circulation/blowout and fracturing formation by managing the density of the drilling fluid, but also improves productivity by mitigating reservoir damage. Calculating the geothermal pressure of a geothermal well by constant parameters would easily bring big errors, as the changes of physical, rheological and thermal properties of drilling fluids with temperature are neglected. This paper researched the wellbore pressure coupling by calculating the temperature distribution with the existing model, fitting the rule of density of the drilling fluid with the temperature and establishing mathematical models to simulate the wellbore pressures, which are expressed as the variation of Equivalent Circulating Density (ECD) under different conditions. With this method, the temperature and ECDs in the wellbore of the first medium-deep geothermal well, ZK212 Yangyi Geothermal Field in Tibet, were determined, and the sensitivity analysis was simulated by assumed parameters, i.e., the circulating time, flow rate, geothermal gradient, diameters of the wellbore, rheological models and regimes. The results indicated that the geothermal gradient and flow rate were the most influential parameters on the temperature and ECD distribution, and additives added in the drilling fluid should be added carefully as they change the properties of the drilling fluid and induce the redistribution of temperature. To ensure the safe drilling and velocity of pipes tripping into the hole, the depth and diameter of the wellbore are considered to control the surge pressure.

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A Comprehensive Mechanistic Model for Upward Two-Phase Flow in Wellbores

Cited by 272 publications

References 22 publications

Two-Phase Flow in Pipes: Numerical Improvements and Qualitative Analysis for a Refining Process

Two-Phase Flow in Pipes: Numerical Improvements and Qualitative Analysis for a Refining Process

Equivalent Circulation Density Analysis of Geothermal Well by Coupling Temperature

Equivalent Circulation Density Analysis of Geothermal Well by Coupling Temperature

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