Effect of Xanthan gum on rheological properties of water - crude oil emulsions

This study investigated the effect of Xanthan Gum on the stability, microstructure, and rheological properties of water/crude oil emulsions using the Rheometer DRH2, a centrifuge, and an optical microscope. The results show a decrease in the diameter of the water globules for Xanthan Gum quantities less than 0.2 wt (%), which leads to the stability of the emulsions of water/ crude oil. However, it increases when Xanthan Gum quantities are greater than 0.2 wt%, indicating a destabilization of the emulsions. Moreover, the flow curves for all formulated emulsions were analysed using the Herschel-Bulkley model, which showed that the yield stress increased with the addition of Xanthan Gum. Dynamic tests were conducted under a specific range of applied shear stress to define the emulsions’ behavior, revealing viscoelasticity. The Xanthan Gum expands the linear viscoelastic region and improves the thickness of the emulsion.