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

摘要： 低浓度交联聚合物技术,可以解决策合物驱技术中所存在的聚合物用量高,耐温抗盐性能差的问题,成为EOR技术领域中一个新的技术发展方向。采用改进的难类有机交联剂和高相对分子质量的部分水解聚丙烯酰胺(HPAM),开展了以改善聚合物驱为目的的低浓度交联聚合物体系研究。研究结果表明,该体系具有很强的成胶能力,HPAM浓度为150～300mg/L,交联剂浓度为50～130mg/L的体系,75～90℃条件下老化180d,粘度值保持在406～94.6mPa·s。与聚合物驱技术相比,可以大幅度地降低化学剂用量。该体系耐温可达90℃,耐矿化度可达100000mg/L,并且可以用污水(油田产出水)配制,表现出优异的耐温抗盐性能,可以在更高温度和矿化度的油藏使用,扩展了HPAM的应用领域和范围,显示出良好的应用前景。同时对交联反应机理进行了初步探索,认为交联剂和HPAM之间的反应主要是HPAM分子间的交联反应,HPAM分子链卷曲收缩有利于分子间交联反应发生。因此,选用低水解度HPAM和提高水的矿化度有利于提高文联HPAM溶液的性能。

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