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Separator Gas Capacity at Standard Conditions Formula

qs=67824Ksd2Fg1zPPsTsT(ρlρgρg)0.5q_s=67824K_sd^2F_g\frac{1}{z}\frac{P}{P_s}\frac{T_s}{T}\left(\frac{\rho_l-\rho_g}{\rho_g}\right)^{0.5}

Separator Gas Capacity at Standard Conditions calculates gas capacity at standard conditions for well performance workflows in production engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (K_s, d, F_g, z, P, P_s, T, T_s, rho_l, rho_g) are known and the assumptions behind the cited well performance relationship match the engineering case being checked.

Assumptions

  • Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
  • The declared units match the field-unit constants used in the formula.
  • The cited formula applies to the selected petroleum engineering workflow.

Limitations

  • The calculation does not replace a full engineering model or operating procedure.
  • Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.

Common mistakes

  • Mixing unit systems without converting the inputs.
  • Using default example values as field recommendations.
  • Applying the formula outside the source assumptions.

Default example

Using the default inputs, q_s equals 50,624,861.2409 ft3/d.

K_sft/s

0.35

dft

4

F_gfraction

0.75

zdimensionless

0.9

Ppsi

800

P_spsi

14.7

TK

600

T_sK

520

rho_lg/cm3

0.75

rho_gg/cm3

0.06

Inputs

K_s

ft/s

Separator Coefficient

d

ft

Total Internal Diameter of Separator

F_g

fraction

Fraction of Total Area Available to Gas

z

dimensionless

Gas Compressibility Factor

P

psi

Separation Pressure

P_s

psi

Base Pressure

T

K

Absolute Separation Temperature

T_s

K

Base Temperature

rho_l

g/cm3

Liquid Density

rho_g

g/cm3

Gas Density

Outputs

q_s

ft3/d

Gas Capacity at Standard Conditions

K_s

ft/s

Separator Coefficient

d

ft

Total Internal Diameter of Separator

F_g

fraction

Fraction of Total Area Available to Gas

Source and review

reviewed

Gas Conditioning and Processing, Campbell, J. M. (1992)

John M. Campbell. 1992. Gas Conditioning and Processing, Campbell Petroleum Series, Vol. 2, Page 74.

Source

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