Synthesis of a low viscosity amphoteric polyacrylamide and its application in oilfield profile control

A low viscosity amphoteric polyacrylamide (LHPAM) was synthesized with Acrylamide and a Cationic etherifying agent. FTIR, SEM, and EDS all suggest that it successfully synthesized a new material. It can be demonstrated from TG and DSC that the temperature resistance of LHPAM is higher than that of partially hydrolyzed polyacrylamide (HPAM) and it can be found from ultraviolet-visible spectrophotometer that the flocculability of LHPAM is stronger than that of HPAM. The viscosity testing shows that the viscosity of LHPAM is greater than that of HPAM at the beginning, but the viscosity of LHPAM has been ultimately lower than that of HPAM after 1d. In addition, LHPAM reacts with Cr3+ to form a gel with an interpenetrating network structure, while HPAM is a gel with a comb-shaped system, and the gelation time of LHPAM is longer than that of HPAM. However, the final gelation strength is the same. The final flow experiment shows that the plugging rates of LHPAM and HPAM are greater than 95%, but the resistance coefficient of LHPAM is smaller than that of HPAM. This study expands the application of HPAM in profile control and water shutoff, which is of great significance for enhanced oil recovery.