Contact Angle from Interfacial Tensions Formula
Contact Angle from Interfacial Tensions calculates contact angle for rock properties workflows in petrophysics.
How engineers use this formula
Use this formula when the listed inputs (sigma_so, sigma_sw, sigma_wo) are known and the assumptions behind the cited rock 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, theta equals 60 degree.
50
30
40
Inputs
sigma_so
dyn/cmSolid-Oil Interfacial Tension
sigma_sw
dyn/cmSolid-Water Interfacial Tension
sigma_wo
dyn/cmWater-Oil Interfacial Tension
Outputs
theta
Contact Angle
sigma_so
Solid-Oil Interfacial Tension
sigma_sw
Solid-Water Interfacial Tension
sigma_wo
Water-Oil Interfacial Tension
Source and review
reviewedPetrophysics: Theory and Practice of Measuring Reservoir Rock and Fluid Transport Properties, Tiab, D., Donaldson, E. C. (2015)
Tiab, D. and Donaldson, E. C. 2015. Petrophysics: Theory and Practice of Measuring Reservoir Rock and Fluid Transport Properties. Gulf Professional Publishing, Page 362.
Source