Gas/Oil Interfacial Tension

Gas/Oil Interfacial Tension

Gas/Oil Interfacial Tension correlation was published by Baker and Swerdloff in 1956.

File:Gas/Oil Interfacial Tension.png

Gas/Oil Interfacial Tension correlation in the PVT software at pengtools.com

Math and Physics

$\sigma_{68} =39 - 0.2571 SG_{oAPI}$

$\sigma_{100} =37.5 - 0.2571 SG_{oAPI}$

$At\ T<68F,\ \sigma_{od}=\sigma_{68}$

$At\ 68F<T<100F,\ \sigma_{od}=\frac{\sigma_{68} + (T - 68) * (\sigma_{100} - \sigma_{68})}{ (100 - 68)}$

$At\ T>100F,\ \sigma_{od}=\sigma_{100}$

$\sigma_{o}=\sigma_{od} \times (1-0.24P^{0.45})$

The interfacial tension becomes zero at miscibility pressure, and for most systems this is at any pressure greater than about 5000 psia. Once the correction factor becomes zero (at about 3977 psia), 1 dyne/cm is used for calculations.

$if (\sigma_{o}<1) \sigma_{o}=1$

Nomenclature

$P$ = pressure, psia

$\sigma_{o}$ = gas/oil interfacial tension, dynes/cm

$\sigma_{od}$ = gas/oil interfacial tension for dead oil, dynes/cm

$T$ = temperature, °F

References

Baker, O. and Swerdloff, W. 1955. Calculation of Surface Tension 3—Calculating parachor Values. Oil Gas J. (5 December 1955): 141. Baker, O. and Swerdloff, W. 1956. Calculation of Surface Tension 6—Finding Surface Tension of Hydrocarbon Liquids. Oil Gas J. (2 January 1956): 125.