关键词: 交联聚合物, 交联剂, 聚丙烯酰胺, 耐温抗盐, 粘度, 长期稳定性

Abstract: The polymer flooding technology has been widely used in oilfield successfully. But there are problems such as high polymer concentration and unstability in high salinity brines at elevated temperature. The technology of low concentration crosslinking HPAM can solve these problems. The improved organic crosslinker and high molecular weight HPAM are adopted to investigate the system of crosslinking HPAM for flooding application. The experimental results show that gelling ability of this system is excellent at high temperature and salinity conditions. The crosslinking HPAM system of 150~300mg/L HPAM and 50~130mg/L crosslinker has been aged for 180 days at 75~90℃,its viscosity values maintain between 40.6~94.6 mPa·s. Compared with polymer flooding, the amounts of HPAM used can be obviously reduced. This system can tolerate harsh reservoir conditions (high temperature of 90℃ and high salinity of 100000 mg/L),so it offers the possibility to extend the upper temperature and salinity limit significantly for the use of HPAM in polymer flooding. The mechanism of reaction is mainly intermolecular crosslinking reaction between HPAM chain. The more coiling and shrinkage the HPAM chain, the more easily intermolecular crosslinking reaction takes place. The properties of crosslinking HPAM system may be improved by selecting lower hydrolysis degree HPAM and higher salinity brines.

Key words: crosslinking polymer, crosslinker, polyacrylamide, high temperature, salinity