Effect of Hydrophobic Association and Polymer Concentration on Viscoelasticity of Amphiphilic Polymer

Abstract

The viscoelasticity of the polymer for flooding affects the oil displacement efficiency, and the polymer with viscoelastic properties can increase the oil recovery. In this study, the effect of hydrophobic association on the viscoelasticity of the amphiphilic polymer was investigated by rheometer. The critical association concentration (CAC) of the amphiphilic polymer was determined by the relationship curve between zero shear viscosity and polymer concentration, which is about 800 mg/L. With the increasing of amphiphilic polymer concentration, its viscoelasticity exhibits different characteristics and can be converted from a viscous fluid to an elastomeric fluid. The influence mechanism of hydrophobic association on viscoelasticity of amphiphilic polymer was studied by cohesive energy and scanning electron microscope (SEM). The cohesive energy of the amphiphilic polymer increased from 1.26 × 10⁻⁴ Pa to 9.25 × 10⁻² Pa when the amphiphilic polymer concentration ranged from 500 to 1200 mg/L. Larger supra-molecular aggregates and stronger network structures can be formed when the amphiphilic polymer concentration is higher than the CAC. The results show that the viscoelasticity of amphiphilic polymer is related to the concentration of amphiphilic polymer and the association strength. This study has certain guiding significance for the application of amphiphilic polymer in oil and gas field development.

Copyright 2017, Shaanxi Petroleum Society.

This paper was prepared for presentation at the 2017 International Petroleum and Petrochemical Technology Conference in Beijing, China, 20–22 March, 2017.

This paper was selected for presentation by the IFEDC&IPPTC Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the IFEDC&IPPTC Committee and are subject to correction by the author(s). The material does not necessarily reflect any position of the IFEDC&IPPTC Committee, its members. Papers presented at the Conference are subject to publication review by Professional Committee of Petroleum Engineering of Shaanxi Petroleum Society. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of Shaanxi Petroleum Society is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of IFEDC&IPPTC. Contact email: paper@ifedc.org or paper@ipptc.org.