Experimental Investigation of Crude Oil- Xanthan Emulsions Flow Behavior

摘要

The rheological behaviors of crude oil-xanthan gum emulsions were studied in terms of viscosity-shear rate and shear stress-shear rate to understand the flow behavior of these emulsions. Understanding the interaction of oil-droplets phase within the aqueous continuous phase is necessary for the oil displacement mechanism by polymer solution during the enhanced oil recovery stage, thus flow behaviors of crude oil-xanthan gum emulsions were experimentally investigated. The observed rheological behavior was modeled using available mathematical models. Rheostress RS100 was employed throughout this investigation for measuring and analyzing the experimental measurements. A cone and plate of RS100 rheometer was utilized for this investigation. During the shear rate sweep over the range of 0.1-1000 s~(-1), the measurements of shear stress and viscosity of different emulsions were investigated versus shear rate. The xanthan gum concentration range of 500-10~4 ppm (i.e. 0.05-1.0 wt %) was examined. Different crude oil concentrations over the range of 25-75% by volume were tested. A detailed investigation of the flow behavior of crude oil-xanthan gum emulsions was completed. Light concentration of crude oil-water emulsion exhibited Newtonian behavior, however the medium and high crude oil-water emulsions concentrations showed non-Newtonian of shear thinning behavior. All examined aqueous solutions of xanthan gums showed non-Newtonian profile in which their measured viscosity decreased with shear rate. The flow behavior of crude oil-gum emulsion exhibited non-Newtonian of shear thinning behavior that can be presented by Casson model.