API RP 14E Two-Phase Flowline Pressure Drop Calculator
Enter the required inputs, confirm the units, and run the calculator to solve DeltaP_100. Review the formula source and assumptions before using the result in engineering work.
Calculation context and source notes
API RP 14E Two-Phase Flowline Pressure Drop calculates two-phase flowline pressure drop per 100 ft for well performance workflows in production engineering. The page keeps the declared variables, units, source relationship, and output definition visible for technical review.
Use this formula when the listed inputs (f, W, D_i, rho_m) are known and the assumptions behind the cited well performance relationship match the engineering case being checked.
Solves for
DeltaP_100 (psi/100 ft)
Best next page
Formula, variables, and sourceFormula, variables, and default calculation
Reproducible default result
With the default values shown below, the calculation returns DeltaP_100 = 3.9896 psi/100 ft. Defaults demonstrate the implementation; they are not recommended field values.
0.0196
46482.8
3.15
11.5
Input definitions
f
dimensionlessMoody Friction Factor
W
lb/hrTotal Liquid Plus Vapor Weight Flow Rate
D_i
inPipe Inside Diameter
rho_m
lb/ft3Gas-Liquid Mixture Density
Output definitions
DeltaP_100
Two-Phase Flowline Pressure Drop per 100 ft
f
Moody Friction Factor
W
Total Liquid Plus Vapor Weight Flow Rate
D_i
Pipe Inside Diameter
rho_m
Gas-Liquid Mixture Density
Engineering use, assumptions, and limits
Use this formula when the listed inputs (f, W, D_i, rho_m) 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.
Frequently asked questions
What inputs does the API RP 14E Two-Phase Flowline Pressure Drop calculator need?
The calculation uses Moody Friction Factor (f), Total Liquid Plus Vapor Weight Flow Rate (W), Pipe Inside Diameter (D_i), Gas-Liquid Mixture Density (rho_m). Enter values on the units shown beside each field.
What result does this calculator return?
The primary result is two-phase flowline pressure drop per 100 ft in psi/100 ft. The formula section shows the declared relationship, variables, and a reproducible default calculation.
What should I check before using the result?
Confirm the unit basis, source applicability, and input quality. The calculation does not replace a full engineering model or operating procedure. Mixing unit systems without converting the inputs.
Source and record status
Source metadata identifies the relationship implemented by the calculator. Check the cited edition, unit basis, and scope against the engineering case before operational use.
API RP 14E Section 2.5 pressure-drop equation for gas/liquid two-phase steel piping.
Open source reference