Phase Behavior and ThermodynamicsFluid Properties
Baker-Swerdloff Dead-Oil Gas-Oil Interfacial Tension Formula
Baker-Swerdloff Dead-Oil Gas-Oil Interfacial Tension calculates dead-oil gas-oil interfacial tension for fluid properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (API, T) are known and the assumptions behind the cited fluid properties 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, sigma_od equals 29.439 dynes/cm.
APIAPI
35
Tdeg F
80
Inputs
API
APIStock-Tank Oil API Gravity
T
deg FTemperature
Outputs
sigma_od
dynes/cm
Dead-Oil Gas-Oil Interfacial Tension
sigma_68
dynes/cm
Dead-Oil Gas-Oil Interfacial Tension at 68 F
sigma_100
dynes/cm
Dead-Oil Gas-Oil Interfacial Tension at 100 F
T
deg F
Temperature
Source and review
reviewedGas/Oil Interfacial Tension, Baker, O., Swerdloff, W., Pengtools
Baker, O. and Swerdloff, W. 1956. Calculation of Surface Tension 6; Pengtools Gas/Oil Interfacial Tension summary.
Source