Surfactant polymer flooding enhanced oil recovery: optimum polymer injection rate

SP flooding (SP) is one of the most promising EOR techniques after primary and secondary recovery are no longer economical. However, polymer flooding can cause to formation damage due to irreversible polymer adsorption. Meanwhile, surfactant flooding is sensitive to temperature where degradation and precipitation can occur. This research was conducted to study the effectiveness of industrial water treatment Sulfocat BK80 in EOR process and to determine the optimum injection rate of Xanthan gum polymer from 0.25ml/min to 0.55ml/min in the sandpack flooding. Sixteen different SP formulations were designed at using different concentration of Xanthan gum and Sulfocat BK80. These formulations were characterized in terms of density, viscosity, shear rate and solubility in order to identify the optimum SP formulations. From the screening result, Sulfocat BK80-Xanthan gum exhibit nonNewtonian behaviour and Winsor Type II. The optimum concentration of Sulfocat BK80 and Xanthan gum were 3000ppm and 400ppm. The optimum SP formulations were applied in sandpack flooding experiment afterward. In the aspect of Xanthan gum injection rate, the result showed that the lowest and highest injection rate were not suitable in sandpack flooding. Intermediate Xanthan gum injection rate (0.40ml/min) was the optimum injection rate which produced the highest incremental oil recovery up to 7.7% and has better displacement effect. The highest the injection rate of polymer has a better displacement effect, however it contributes to fingering process