Selection of emulsification system for high temperature and high salt reservoir and evaluation of reservoir adaptability

In this study, based on X reservoir conditions from Dagang Oilfield, China (temperature: 104 degrees C, salinity: 26376 mg/L), from the perspective of reducing interfacial tension and emulsification performance, IAPES (isododecyl alcohol polyoxyethylene ether sulfonate) with high temperature and high salt resistance was selected and its performance was evaluated. Finally, physical simulation experiments were conducted to form an in situ viscosity-increasing emulsion to enhance oil displacement efficiency. The experimental results show that when the concentration of IAPES is 0.3 wt%, the ability to reduce the interfacial tension of oil and water is significant and it has good antiaging stability. In addition, the lower the shear rate, the higher the water content, and the worse the emulsion stability. Finally, physical simulation experiments show that IAPES can increase the recovery rate by at least 28% in a larger permeability range. Under the experimental research conditions, the injection process parameters-injection speed (0.4 mL min(-1)) and injection volume (0.3PV) were optimized.

Automated summary

This study selected IAPES with high temperature and high salt resistance to enhance oil displacement efficiency and conducted physical simulation experiments to verify its capability. The research covers reducing interfacial tension and improving recovery rate.