Wet Gas Correction Factors

Correction for Condensates

This page takes a resulting mass flowrate (from an ISO 5167 calculation for example) and applies the necessary correction factors to take account for condensates in the measured flow.


Condensate Density



The condensate density is required when calculating the total liquid density. The next five steps are required to calculate the condensate density. If the configuration option -

Condensate Stream Density - User Input

is selected this is skipped and the user entered value is used instead.

Compressibility Factor


WetGas_Compressibility Mass

Symbol Description Units
Fpm Compressibility factor -
tm Stream temperature °C
ρs Condensate standard density kg/Sm3


Constant Value
a -1.62080
b 0.00021592
c 0.87096
d 0.0042092

Condensate Pressure Correction Factor


WetGas_PressureCorrect

Symbol Description Units
Cplm Condensate pressure correction factor -
Fpm Compressibility factor -
pm Stream pressure bar g

Coefficient of Thermal Expansion


API_11.2.1_Thermal_Expansion

tr>
Symbol Description Units
αr Coefficient of thermal expansion -
ρstd Standard condensate density kg/Sm3
APIk0 From calibration certificate -
APIk1 From calibration certificate -
APIk2 From calibration certificate -

Temperature Correction Factor


WetGas_TemperatureCorrect

Symbol Description Units
Ctlm Temperature correction factor -
α Coefficient of thermal expansion -
tm Stream temperature °C
ts Standard temperature °C

Condensate Density


WetGas_CondensateDensity

Symbol Description Units
ρm Condensate density kg/m3
ρs Condensate standard density kg/Sm3
Cplm Condensate pressure correction factor -
Ctlm Condensate temperature correction factor -

Water Density


WetGas_WaterDensity

Symbol Description Units
ρm,w Water stream density kg/m3
t1 Gas upstream temperature °C
ρs,w Water standard density kg/Sm3
ts Gas standard temperature °C


Constant Value
D -0.0001732
E -0.1307
F 1040

Methanol Density


WetGas_MethanolDensity

Symbol Description Units
ρm,m Methanol stream density kg/m3
t1 Gas upstream temperature °C
ρs,m Methanol standard density kg/Sm3
ts Gas standard temperature °C


Constant Value
G 7.13E-05
H -0.3344
J 540

Liquid to Gas Ratio


WetGas_LtoGRatio

Symbol Description Units
φl Liquid to gas mass ratio -
φc Operator entered condensate to gas mass ratio -
φw Operator entered water to gas mass ratio -
φm Operator entered methanol to gas mass ratio -

Wet Gas Mass Fractions


WetGas_MassFraction

Symbol Description Units
Xg Wet gas mass fraction -
φl Liquid to gas mass ratio -

Liquid Component Mass Fractions


WetGas_LiquidCompMassFraction

Symbol Description Units
Xg Wet gas mass fraction -
Xc Condensate mass fraction -
Xw Water mass fraction -
Xm Methanol mass fraction -
φc Operator entered condensate to gas mass ratio -
φw Operator entered water to gas mass ratio -
φm Operator entered methanol to gas mass ratio -

Liquid Density


WetGas_LiquidDensity

Symbol Description Units
ρl Liquid density kg/m3
ρc Condensate stream density kg/m3
ρw Water stream density kg/m3
ρm Methanol stream density kg/m3
φl Liquid to gas mass ratio -
φc Operator entered condensate to gas mass ratio -
φw Operator entered water to gas mass ratio -
φm Operator entered methanol to gas mass ratio -

Lockhart-Martinelli Factor - Orifice Meter



The following calculation is carried out if any correction factor other than the Steven correction factor is selected.
WetGas_Lockhart

Symbol Description Units
FLM Lockhart-Martinelli factor -
Xg Gas mass fraction -
ρg Gas density kg/m3
ρl Liquid density kg/m3

Froude Number - Orifice Meter



The following calculation is carried out if either the Chisholm or De Leeuw correction factor is selected.
WetGas_FroudeOrifice

Symbol Description Units
Fr Froude Number -
gv Gas velocity -
Re Reynolds Number -
V Fluid viscosity Cp
D Corrected pipe diameter m
ρg Gas density kg/m3
ρl Liquid density kg/m3


Gravitational Constant Value
g 9.80664999999999

Murdock Correction Factor


WetGas_Murdock

Symbol Description Units
Fadj Murdock correction factor -
M Operator entered Murdock Factor(default = 1.26) -
FLM Lockhart Martinelli factor -
ε Gas expansion factor -
Cg Gas coefficient of discharge -
Cl Liquid coefficient of discharge -

Chisholm Correction Factor



If the Froude Number is below 0.5 the Chisholm correction factor = 1.
WetGas_DeLeeuw3

Symbol Description Units
Fadj Chisholm correction factor -
FLM Lockhart Martinelli factor -
ρl Liquid density kg/m3
ρg Gas density kg/m3
n Operator entered Chisholm Factor(default = 0.25) -

De Leeuw Correction Factor



For Froude Numbers above 1.5:
WetGas_DeLeeuw
For Froude Numbers below 1.5:
WetGas_DeLeeuw1
De Leeuw Correction
WetGas_DeLeeuw2

Symbol Description Units
Fadj De Leeuw correction factor -
Frg Froude Number -
FLM Lockhart Martinelli factor -
ρl Liquid density kg/m3
ρg Gas density kg/m3
n De Leeuw Factor -

Steven Correction Factor (The following steps are only carried out when the 'Steven Factor' is selected.)



Because the corrected mass flow rate is used to calculate the Steven correction factor an iterative method is required. The following calculations iterate up till the previous mass flowrate less than 0.00001 out from the current mass flowrate or a maximum of 100 iterations is reached.

Inlet Area of the V-Cone Meter


WetGas_InletAreaCone

Symbol Description Units
A Inlet area of the v-cone meter at operating conditions m2
D Internal pipe diameter at working conditions m

Liquid Mass Flowrate


WetGasF_LiquidMass

Symbol Description Units
qml Liquid mass flowrate kg/s
qm Gas corrected mass flowrate kg/s
φl Liquid to gas mass ratio -



Lockhart-Martinelli Factor



For configuration option: Include Clamping - Yes
If the density ratio is less than 0.027 the ratio is clamped to 0.027
WetGas_LockhartCone

Symbol Description Units
FLM Lockhart-Martinelli factor -
qml Liquid mass flowrate kg/s
qm Gas corrected mass flowrate kg/s
ρg Gas density kg/m3
ρl Liquid density kg/m3



Superficial Gas Velocity


WetGas_SuperficialVelocity

Symbol Description Units
Usg Superficial gas velocity m/s
qm Uncorrected mass flowrate kg/s
ρg Gas density kg/m3
A Inlet area of the v-cone meter at operating conditions m2

Froude Number - Cone Meter


WetGas_FroudeCone

Symbol Description Units
Fr Froude Number -
D Corrected pipe diameter m
ρg Gas density kg/m3
ρl Liquid density kg/m3
Usg Superficial gas velocity -


Gravitational Constant Value
g 9.80664999999999

Wet Gas Correlation Factor A



For configuration option: Include Clamping - Yes
If the density ratio is less than 0.027 the ratio is clamped to 0.027

If the entered beta ratio is less than 0.65 the calculation for A0.55 is used

If the entered beta ratio is more than 0.65 the calculation for A0.75 is used
WetGas_A_Correction

Symbol Description Units
A0.55 Correlation factor for a 0.55 Beta V-Cone meter -
A0.75 Correlation factor for a 0.75 Beta V-Cone meter -
ρl Liquid density kg/m3
ρg Gas density kg/m3

Wet Gas Correlation Factor B



For configuration option: Include Clamping - Yes
If the density ratio is less than 0.027 the ratio is clamped to 0.027

If the entered beta ratio is less than 0.65 the calculation for A0.55 is used

If the entered beta ratio is more than 0.65 the calculation for A0.75 is used
WetGas_B_Correction

Symbol Description Units
A0.55 Correlation factor for a 0.55 Beta V-Cone meter -
A0.75 Correlation factor for a 0.75 Beta V-Cone meter -
ρl Liquid density kg/m3
ρg Gas density kg/m3

Wet Gas Correlation Factor C



For configuration option: Include Clamping - Yes
If the density ratio is less than 0.027 the ratio is clamped to 0.027

If the entered beta ratio is less than 0.65 the calculation for A0.55 is used

If the entered beta ratio is more than 0.65 the calculation for A0.75 is used
WetGas_C_Correction

Symbol Description Units
A0.55 Correlation factor for a 0.55 Beta V-Cone meter -
A0.75 Correlation factor for a 0.75 Beta V-Cone meter -
ρl Liquid density kg/m3
ρg Gas density kg/m3

Steven Correction Factor


WetGas_StevenCorrect

Symbol Description Units
Fadj Steven correction factor -
FLM Lockhart-Martinelli factor -
Frg Froude number -
A Wet gas correlation factor -
B Wet gas correlation factor -
C Wet gas correlation factor -

Corrected Mass Flowrate


WetGas_CorrectedMassFR
Dependant on users selection the wet gas correction factor could be the Steven Correction Factor, the Murdock Correction Factor, the Chisholm Correction Factor or the De Leeuw Correction Factor.


Symbol Description Units
qcorr Corrected mass flowrate kg/s
qISO Uncorrected mass flowrate -
Fadj Wet gas correction factor -

References