An oil-tolerant and salt-resistant aqueous foam system for heavy oil transportation.

Graphical abstract A new oil-tolerant and salt-resistant aqueous foam system was screened out via orthogonal method as a possible lubricant to enable cold heavy oil transportation, whose corresponding ingredients are comprised of 1 g/L sodium lauryl polyoxyethylene ether (AES) +3 g/L sodium alpha-olefin sulfonate (AOS) +3 g/L xanthan gum (XG) +4 g/L hydroxyethyl cellulose (HEC). Highlights • A new aqueous foam system is screened out for heavy oil transportation. • New foam rheological and free drainage models are established. • The foam with multilayered shells belongs to a special microcellular foam. • The foam can maintain stability at high oil and salt concentrations. Abstract An oil-tolerant and salt-resistant aqueous foam system was screened out as a possible lubricant to enable cold heavy oil transportation. The microstructures and viscoelasticity and effects of heavy oil, salt and temperature on the foam stability were investigated and new rheological and drainage models were established. The results indicate the foam with multilayered shells belongs to a special microcellular foam. The viscoelasticity could be neglected due to its low relaxation time. The drainage process can be divided into three stages. The foam with quality of 67.9% maintains great stability at high oil and salt concentrations and appropriate elevated temperature. [ABSTRACT FROM AUTHOR]