Difference between revisions of "Griffith correlation"

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== Discussion  ==
 
== Discussion  ==
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[[Griffith correlation]] adds a hook to the originally straight [[Hagedorn and Brown]] [[VLP]] curve.
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== Nomenclature  ==
 
== Nomenclature  ==
  
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:<math> D </math> = pipe diameter, ft
 
:<math> H_g </math> = gas holdup factor, dimensionless
 
:<math> H_g </math> = gas holdup factor, dimensionless
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:<math> f </math> = friction factor, dimensionless
 
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:<math> GLR </math> = gas-liquid ratio, scf/bbl
 
 
:<math> L_B </math> = bubble-slug boundary, dimensionless
 
:<math> L_B </math> = bubble-slug boundary, dimensionless
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:<math> M </math> = total mass of oil, water and gas associated with 1 bbl of liquid flowing into and out of the flow string, lb<sub>m</sub>/bbl
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:<math> v_g </math> = gas velocity, ft/sec
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:<math> N_D </math> = pipe diameter number number, dimensionless
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:<math> v_L </math> = liquid velocity, ft/sec
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:<math> N_GV </math> = gas velocity number, dimensionless
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:<math> v_s </math> = 0.8, slip velocity (difference between average gas and liquid velocities), ft/sec
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:<math> N_L </math> = liquid viscosity number, dimensionless
 
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:<math> N_LV </math> = liquid velocity number, dimensionless
 
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:<math> p </math> = pressure, psia
 
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:<math> q_c </math> = conversion constant equal to 32.174, lb<sub>m</sub>ft / lb<sub>f</sub>sec<sup>2</sup>
 
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:<math> q_L </math> = total liquid production rate, bbl/d
 
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:<math> Re </math> = Reynolds number, dimensionless
 
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:<math> R_s </math> = solution gas-oil ratio, scf/stb
 
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:<math> SG </math> = specific gravity, dimensionless
 
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:<math> T </math> = temperature, °R or °K, follow the subscript
 
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:<math> v </math> = velocity, ft/sec
 
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:<math> WOR </math> = water-oil ratio, bbl/bbl
 
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:<math> z </math> = gas compressibility factor, dimensionless
 
  
 
== References ==
 
== References ==
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[[Category:pengtools]]
 
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[[Category:pqPlot]]
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[[Category:PQplot]]
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{{#seo:
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|title=Griffith correlation
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|titlemode= replace
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|keywords=Griffith correlation
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|description=Griffith correlation is an empirical correlation which defines: the boundary between the bubble and slug flow.
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}}

Latest revision as of 09:27, 6 December 2018

Brief

The Griffith correlation [1] is an empirical correlation which defines:

  • The boundary between the bubble and slug flow[2]
  • The void fraction of gas in bubble flow - gas hold up Hg[2]

Math & Physics

The bubble flow exist when:

\frac{v_g}{v_g + v_L} < L_B [3]
L_B = 1.071 - 0.2218 \frac{(v_g+v_L)^2}{D}, with the limit L_B \geqslant 0.13 [2]

The gas holdup:

H_g = \frac{1}{2}\ \left ( 1 + \frac{v_g+v_L}{v_s} - \sqrt{ \left ( 1 + \frac{v_g+v_L}{v_s} \right )^2 - 4 \frac{v_g}{v_s}} \right ) [2]

Discussion

Griffith correlation adds a hook to the originally straight Hagedorn and Brown VLP curve.

Nomenclature

D = pipe diameter, ft
H_g = gas holdup factor, dimensionless
L_B = bubble-slug boundary, dimensionless
v_g = gas velocity, ft/sec
v_L = liquid velocity, ft/sec
v_s = 0.8, slip velocity (difference between average gas and liquid velocities), ft/sec

References

  1. ↑ Griffith, P.; Wallis, G. B. (August 1961). "Two-Phase Slug Flow"Paid subscription required. Journal of Heat Transfer. ASME. 83: 307–320. 
  2. ↑ 2.0 2.1 2.2 2.3 Orkiszewski, J. (June 1967). "Predicting Two-Phase Pressure Drops in Vertical Pipe"Paid subscription required. Journal of Petroleum Technology. SPE. 19 (SPE-1546-PA). 
  3. ↑ Economides, M.J.; Hill, A.D.; Economides, C.E.; Zhu, D. (2013). Petroleum Production Systems (2 ed.). Westford, Massachusetts: Prentice Hall. ISBN 978-0-13-703158-0. 
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