Interfacial Tension Correlations

Status: ⚠️ Limited Information — Primary references for Baker-Swerdloff and Abdul-Majeed IFT correlations not available in current reference materials. Document provides general context pending reference acquisition.

Overview

Interfacial tension (IFT) is the force acting at the interface between two immiscible fluids. In petroleum engineering, gas-oil interfacial tension is important for:

• Multiphase flow — affects flow pattern transitions in pipes
• Wellbore hydraulics — influences bubble size and slip velocity
• Enhanced oil recovery — critical parameter for miscibility and displacement
• Separator design — impacts droplet coalescence and separation efficiency

This document covers empirical correlations for estimating gas-oil interfacial tension from fluid properties.

Theory

Physical Significance

Interfacial tension arises from imbalanced intermolecular forces at fluid interfaces. For gas-oil systems:

• Decreases with pressure — approaching zero at critical conditions
• Decreases with temperature — higher molecular mobility reduces surface forces
• Depends on composition — lighter components reduce IFT
• Affects capillary forces — determines fluid distribution in porous media

Typical Values

Correlations

Interfacial tension correlations are typically used in multiphase flow calculations (Beggs-Brill, Hagedorn-Brown) where IFT affects flow pattern transitions and pressure drop predictions.

Common IFT Estimation Methods

Several approaches exist for estimating gas-oil interfacial tension:

1. Empirical correlations — Functions of pressure, temperature, and fluid properties
2. Parachor method — Based on liquid and vapor densities and molecular weights
3. Corresponding states — Reduced temperature and pressure relationships

Baker-Swerdloff (1956)

The Baker-Swerdloff correlation estimates gas-oil interfacial tension for pipeline flow calculations.

Status: 📚 Reference Not Available — Primary reference not found in current materials.

Primary Reference:

• Baker, O. and Swerdloff, W. (1956). "Calculation of Surface Tension."

Application: Widely used in multiphase flow correlations (Beggs-Brill) for estimating flow patterns and liquid holdup.

Note: This correlation is mentioned in multiphase flow references (Beggs-Brill 1973) as a standard method for obtaining surface tension values needed for flow pattern determination.

Abdul-Majeed Correlation

Status: 📚 Reference Not Available — Correlation details to be determined.

Note: Abdul-Majeed et al. published correlations for oil formation volume factor and oil viscosity. An IFT correlation may exist but was not found in available references. Further research needed to confirm correlation details and publication.

Application: If available, would provide updated IFT estimation for modern reservoir fluids.

Functions Covered

Related Topics

• Gas Properties — Gas density and viscosity
• Oil Viscosity — Oil viscosity correlations
• Pipe Flow Overview — Multiphase flow correlations
• Beggs-Brill Correlation — Uses IFT in flow pattern maps

References

Available References

1. Beggs, H.D. and Brill, J.P. (1973). "A Study of Two-Phase Flow in Inclined Pipes." Journal of Petroleum Technology, May 1973, 607-617. [Available: theory/references/articles/beggs1973.md] — Uses surface tension in flow pattern correlations.

References to Obtain

1. Baker, O. and Swerdloff, W. (1956). "Calculation of Surface Tension." — Primary reference for Baker-Swerdloff IFT correlation.

2. Abdul-Majeed, G.H. — IFT correlation details to be confirmed. Note: Abdul-Majeed et al. (1990) published oil viscosity correlations; IFT correlation reference needs verification.

Related Reading

For background on interfacial tension in petroleum systems:

• McCain, W.D. (1990). Properties of Petroleum Fluids. PennWell Publishing.
• Ahmed, T. (2019). Reservoir Engineering Handbook. Gulf Professional Publishing.
• Dandekar, A.Y. (2013). Petroleum Reservoir Rock and Fluid Properties. CRC Press.
• Economides, M.J. et al. (1994). Petroleum Production Systems. Prentice Hall.

Document Status

Status: 👀 Needs Reference Materials — General IFT context documented. Primary references for Baker-Swerdloff and Abdul-Majeed correlations required for complete documentation.