Production EngineeringWell Performance
API RP 14E Total Wellstream Weight Flow Rate Formula
API RP 14E Total Wellstream Weight Flow Rate calculates total liquid plus vapor weight flow rate for well performance workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (Q_g, S_g, q_L, S_L) 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, W equals 46,482.8 lb/hr.
Q_gMMscf/day
10
S_gspecific gravity
0.65
q_Lbbl/day
1700
S_Lspecific gravity
1.04
Inputs
Q_g
MMscf/dayGas Flow Rate
S_g
specific gravityGas Specific Gravity
q_L
bbl/dayLiquid Flow Rate
S_L
specific gravityLiquid Specific Gravity
Outputs
W
lb/hr
Total Liquid Plus Vapor Weight Flow Rate
Q_g
MMscf/day
Gas Flow Rate
S_g
specific gravity
Gas Specific Gravity
q_L
bbl/day
Liquid Flow Rate
S_L
specific gravity
Liquid Specific Gravity
Source and review
reviewedAPI RP 14E Section 2.5 pressure-drop equation and Appendix A flowline example, weight-flow equation W = 3180 Qg Sg + 14.6 Ql Sl.
SourceRelated formulas and calculators
Effective Wellbore Radius of a Well in Presence of Uniform Flux Fractures
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Effective Wellbore Radius of a Horizontal Well – Method 1 (Anisotropic Reservoirs)
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Effective Wellbore Radius of a Horizontal Well – van der Vlis et al. Method
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