PetroCalcHubFree
Production EngineeringWell Performance

Gilbert Critical Choke Liquid Rate Formula

qL=PwhD641.89435GLR0.546q_L=\frac{P_{wh}D_{64}^{1.89}}{435GLR^{0.546}}

Gilbert Critical Choke Liquid Rate calculates liquid flow rate for well performance workflows in production engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (P_wh, D64, GLR_Mscf) 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_L equals 600.789987 bbl/day.

P_whpsig

460

D6464th inch

22

GLR_MscfMscf/STB

0.4

Inputs

P_wh

psig

Upstream Wellhead Pressure

D64

64th inch

Choke Size

GLR_Mscf

Mscf/STB

Gas-Liquid Ratio

Outputs

q_L

bbl/day

Liquid Flow Rate

P_wh

psig

Upstream Wellhead Pressure

D64

64th inch

Choke Size

GLR_Mscf

Mscf/STB

Gas-Liquid Ratio

Source and review

reviewed

Gilbert, W.E. 1954. Flowing and Gas-Lift Well Performance; public choke-performance summaries.

Source

Related formulas and calculators

Deliverability Equation for Shallow Gas Reservoirs
Well Performance
Effective Wellbore Radius of a Well in Presence of Uniform Flux Fractures
Well Performance
Critical Rate for Horizontal Wells in Edge-Water Drive Reservoirs
Well Performance
Effective Wellbore Radius of a Horizontal Well – Method 1 (Anisotropic Reservoirs)
Well Performance
Effective Wellbore Radius of a Horizontal Well – van der Vlis et al. Method
Well Performance
Joshi Horizontal Well Productivity Index
Well Performance