Preparation and Research of EOR used Microgel with High Resistance to Temperature and Salinity

Abstract： Polyacrylamide (PAM) microgel with low degree of cross-linking was synthesized in this study. Properties such as its water solution viscosity and EOR (enhanced oil recovery) were characterized. The influence of concentration and degree of cross-linking on EOR of the PAM microgel solution was studied. From these results, it is stated that this kind of microgel can improve the resistance to salinity and temperature, and can give an EOR much higher than partially hydrolyzed polyacrylamide (HPAM) solution. In the condition of a salinity of 80000mg/L (Ca2+, Mg2+, Na+), at 45℃ the microgel solution with a degree of cross-linking of 11.4% and a concentration of 1.5‰ have almost the same viscosity as compared with its fresh water solution at room temperature and gives a 25% improving sweep efficiency in laboratory core flooding test. This kind of microgel solution is very useful in chemical enhanced oil recovery process and has potential of industrial utilization.