Difference between revisions of "Fanning correlation"

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Why [[Fanning correlation]] ?
 
Why [[Fanning correlation]] ?
  
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{{Quote| text = The Gray correlation was found to be the best of several initially tested ... | source = Nitesh Kumar l<ref name= Kumar />}}
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[[Fanning correlation]] actually is not a correlation, it's fully explicit workflow to define the pressure drop.
  
 
== Nomenclature  ==
 
== Nomenclature  ==

Revision as of 11:35, 7 April 2017

Brief

The Fanning correlation is the name used to refer to the calculation of the hydrostatic pressure difference and the friction pressure loss for the dry gas.

Fanning correlation is the default VLP correlation for the dry gas wells in the PQplot.

Math & Physics

Following the law of conservation of energy the basic steady state flow equation is:

144 \frac{\Delta p}{\Delta h} = \rho_g + \rho_g \frac{f v_g^2 }{2 g_c D} + \rho_g \frac{\Delta{(\frac{v_g^2}{2g_c}})}{\Delta h}

Colebrook–White [1] equation for the Darcy's friction factor:

\frac{1}{\sqrt{f}}= -2 \log \left( \frac { \varepsilon} {3.7 D} + \frac {2.51} {\mathrm{Re} \sqrt{f}} \right)[2]

Reynolds number:

Re = 1488\ \frac {\rho_g v_g D}{\mu_g}
\rho_g = \frac{28.967\ SG_g\ p}{z\ 10.732\ T_R} [3]
v_{SG} = \frac{q_g \times 10^6}{86400 A_p}\ \frac{14.7}{p}\ \frac{T_K}{520}\ \frac{z}{1}

Discussion

Why Fanning correlation ?

Fanning correlation actually is not a correlation, it's fully explicit workflow to define the pressure drop.

Nomenclature

h = depth, ft
f = friction factor, dimensionless
p = pressure, psia
Re = Reynolds number, dimensionless
SG = specific gravity, dimensionless
T = temperature, °R or °K, follow the subscript
v = velocity, ft/sec
z = gas compressibility factor, dimensionless

Greek symbols

\varepsilon = absolute roughness, ft
\mu = viscosity, cp
\rho = density, lbm/ft3

Subscripts

g = gas
K = °K
L = liquid
R = °R
SG = superficial gas

References

  1. ↑ Colebrook, C. F. (1938–1939). "Turbulent Flow in Pipes, With Particular Reference to the Transition Region Between the Smooth and Rough Pipe Laws"Paid subscription required. Journal of the Institution of Civil Engineers. London, England. 11: 133–156. 
  2. ↑ Moody, L. F. (1944). "Friction factors for pipe flow"Paid subscription required. Transactions of the ASME. 66 (8): 671–684. 
  3. ↑ Lyons, W.C. (1996). Standard handbook of petroleum and natural gas engineering. 2. Houston, TX: Gulf Professional Publishing. ISBN 0-88415-643-5. 

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