Abstract: In order to further explore intramolecular rosslinked gelation mechanism of Cr^3+ polymer gel under different pH conditions, effect of pH on Cr^3+  polymer gel gelation performance was researched. Polymer gelformulation composition with good gelation performance was obtained by orthogonal experiment taking polymer mass concentration, water solution salinity and "polymer/Cr^3+ " as the influence factors, aimed at Daqing Lamadian oilfield geological characteristics and fluid properties. The results showed that acidic conditions could promote ionization of chromium acetate and increase the number of Cr^3+  in solution, thus increase the probability of coordination reaction between carboxyl in polymer chains and polynuclear olation complex ion, which is in favor of the formation of intramolecular crosslinked Cr^3+  polymer gel system. The number of OH^- was increased with solvent water pH, which could result in the reduction of Cr^3+  involved in crosslinking reaction and gelation performance getting worse accordingly. when the system was similar to intramolecular crosslinked Cr^3+  polymer gel, gelation performance of polymer gel system can be further improved by appropriately reducing pH value of solvent water.

Key words: pH,    , Intramolecular rosslinking,    ,  Cr³⁺ polymer gel,     ,  Orthogonal experiment,     , Gelation performance,    ,  Mechanism analysis

摘要： 为进一步探究不同p H条件下C r ³⁺聚合物凝胶“ 分子内” 交联成胶机理, 针对大庆喇嘛甸油田储层地质特征和流体性质, 以聚合物质量浓度、 矿化度调节剂浓度和聚铬比为影响因素, 在通过正交试验优选出成胶效果良好的聚合物凝胶配方组成基础上, 研究了p H对C r ³⁺聚合物凝胶成胶效果影响。结果表明, 酸性条件能够促进醋酸铬的电离, 增大多核羟桥配离子与聚合物分子链上羧基之间发生配位反应的概率, 有利于C r ³⁺聚合物凝胶形成 “ 分子内” 交联结构体系; 随溶剂水p H增加, 溶液中 OH^- 数量增加, 参与交联反应的C r ³⁺ 数量减少, 聚合物凝胶分子内” 交联成胶效果变差; 适当降低溶剂水p H可进一步改善聚合物凝胶“ 分子内” 交联成胶效果。

关键词: p H, &ldquo, 分子内&rdquo, 交联, C r ³⁺聚合物凝胶,  , 正交试验, 成胶效果, 机理分析