缓冲法控制交联聚合物弱凝胶成胶时间

弱凝胶调驱技术是将聚合物与交联剂以及添加剂以单液法的形式注入地层，从而达到深部调驱的目的。针对现有交联聚合物弱凝胶体系的成胶时间过短、不能满足现场深部调驱的要求，通过采取在交联聚合物弱凝胶体系中加入缓冲溶液，借助缓冲溶液对弱凝胶体系ｐH值的调节作用，来达到调节交联剂的成胶时间的目的。通过L9正交实验，并将得到的数据进行极差分析和归一化处理，得出各个反应条件对成胶时间影响程度顺序为：溶液的pH值（因素B）＞交联剂用量（因素A）＞温度（因素C），并且酸性（pH＜7）条件下,成胶时间较长。最后选用５种不同pH的HAc-NaAc缓冲溶液对L-2/HPAM交联聚合物弱凝胶体系的成胶时间进行调节，可以将这一体系的成胶时间从42～384 h进行控制，而成胶强度基本不变化。这达到了用缓冲法来控制交联聚合物弱凝胶体系成胶时间的目的。

Controlling Gel Time of Weak Cross-linked Polymer Gel System by Buffer Method

Weak gel drive technique means to inject the mixture of polymer, cross-linking agent, and additives into the formation for the purpose of deep drive. The gel time of existing weak cross-linked polymer gel system is so short that can't satisfy with the requirement of oil fields. This paper introduces the method of adding buffer that regulates the pH value to weak gel system to control gel time of cross-linked polymer. Through orthogonal test (L9) and differential analysis and normalization processing of data, the degree how the gel time has affected by those factors is in the order of pH value (Factor B)>cross-linked gel quantity (Factor A)>temperature (Factor C). Also, the gel time is longer while pH<7. Adopting five kinds of HAc-NaAc buffer to control the gel time of L-2/HPAM system, the gel time is from 42-384 hours and the gel strength is not changed. So it is concluded that buffer method can control the gel time of cross-linked polymer system.