Difference between revisions of "Dranchuk correlation"

Revision as of 10:49, 25 April 2017

z = 1+ \left(A_1 +\frac{A_2}{T_{pr}} +\frac{A_3}{T^3_{pr}} +\frac{A_4}{T^4_{pr}} +\frac{A_5}{T^5_{pr}} \right)\ \rho_r+ \left(A_6 +\frac{A_7}{T_{pr}} +\frac{A_8}{T^2_{pr}} \right)\ \rho^2_r -A_9\ \left(\frac{A_7}{T_{pr}}+\frac{A_8}{T^2_{pr}}\right) +A_{10}\ \left(1+A_{11}\ \rho^2_r\right)\ \frac{\rho^2_r}{T^3_{pr}} \ e^{-A_{11}\ \rho^2_r}

^[1]

where

T_{pc} = 99.3+180\ SG_g-6.94\ SG^2_g

P_{pc} = 4.6+0.1\ SG_g-0.258\ SG^2_g

T_{pr} = \frac{T}{T_{pc}}

P_{pr} = \frac{P}{P_{pc}}

\rho_r = \frac{0.27\ P_{pr}}{({z\ T_{pr}})}

To avoid the Liquid loading the gas velocity should be above the Liquid loading velocity.

The higher the gas rate the higher the gas velocity.

The lower the wellhead flowing pressure the higher the gas rate.

The bigger the tubing ID the higher the gas rate.

In case when the gas rate is limited by the Reservoir deliverability smaller tubing ID will increase the gas velocity.

z

= gas compressibility factor, dimensionless

P

= Pressure, psia

T

= Temperature, °R

P_{pc}

= Pseudo critical pressure, psia

T_{pc}

= Pseudo critical temperature, °R

SG_g

= gas specific density

↑ Turner, R. G.; Hubbard, A. E.; Dukler (Nov 1969). "Analysis and Prediction of Minimum Flow Rate for the Continuous Removal of Liquids from Gas Wells". Journal of Petroleum Technology (SPE-2198-PA): 1475–1482.

@@ Line 61: / Line 61: @@
 :<math> P </math> = Pressure, psia
 :<math> T </math> = Temperature, °R
+:<math> P_{pc} </math> = Pseudo critical pressure, psia
+:<math> T_{pc} </math> = Pseudo critical temperature, °R
 :<math> SG_g </math> = gas specific density