Could Naphthenic Acids be Responsible for Severe Emulsion Tightness for a Low TAN Value Oil? Part 2: Interfacial Rheology. (ABSTRACT)

摘要

Interfacial rheology of a water/crude oil system was investigated with an oscillating pendant drop tensiometer at different pH and water salinities. The considered crude oil has a low TAN value but behaves like acidic oils (part 1). For low salinity solutions (de-ionized water with addition of strong acid or basis), the rheological behavior was close to that of a Hookean solid with small variations of elastic modulus with frequency and low loss angles. Elastic modulus decreased with increasing pH, suggesting that the interfacial layer became less packed due to electrostatic repulsion between the adsorbed ionized surfactants (RCOO).