Effect of salinity on the IFT between aqueous surfactant solution and crude oil

ABSTRACT

The effect of salts and different surfactants on the equilibrium as well as dynamic interfacial tension (DIFT) between crude oil and water was investigated. Three different types of surfactants with identical hydrophobic chain length C₁₂: Sodium Lauryl Ether Sulphate (SLES), Dodecyl Trimethyl Ammonium Bromide (DTAB), Polyoxyethylene (23) lauryl ether (C₁₂E₂₃) were used in this study. SLES shows better synergism of salt and surfactant mixture amongst the surfactants studied. The order of synergism of salts with the surfactant observed was MgCl₂>CaCl₂> NaCl. The results obtained from partition coefficient study show that the addition of salts favours the partition of surfactants into the oil phase hence reduce IFT more effectively. DIFT results reveal that, salt accelerates the surfactant migration towards the interface, hence, reducing the t^* value.

KEYWORDS:

• interfacial tension
• dynamic interfacial tension
• crude oil
• partition coefficient

Acknowledgement

The authors would like to acknowledge ONGC Uran plant for providing Crude oil sample and University Grants Commission, India for the grant of a fellowship during this work. UGC-BSR grant No. F.5-64/2007.

Additional information

Funding

The authors would like to acknowledge ONGC Uran plant for providing Crude oil sample and University Grants Commission, India for the grant of a fellowship during this work. UGC-BSR grant No. F.5-64/2007.