Experimental investigation of the yield stress measurements for xanthan solutions and crude oil-xanthan emulsions

Yield stress measurements of xanthan aqueous solutions and crude oil-xanthan emulsions were investigated experimentally. The yield stress study was carried out for wide range of crude oil (0-75% by volume) and xanthan gum (0-10(4) ppm) concentrations. Two types of xanthan polymers of Sigma and Kelzan were used for the current study. Aqueous solutions with higher xanthan concentration displayed higher cycles of shear rate-shear stress rheograms. Both aqueous solutions of Sigma and Kelzan showed similar behavior for concentration of 1000ppm, however, Sigma solutions of higher concentrations reported slightly higher flow behavior than Kelzan. Similar rheogram behaviors are found for both Sigma and Kelzan emulsions up to concentration of 5,000ppm. However, for 10,000ppm, a slight higher profile for Sigma emulsions was reported.