交联聚合物溶液的热氧化及剪切安定性对其封堵性能的影响

 摘要：采用核孔膜过滤和动态光散射(DLS)法，研究了高相对分子质量、低浓度的部分水解聚丙烯酰胺(HPAM)与柠檬酸铝(AlCit)反应所形成的交联聚合物溶液(LPS)的热氧化及剪切安定性对其在油藏深部调剖封堵性能的影响及其原因。结果表明，HPAM与AlCit反应所形成的LPS在90℃下热氧化降解24h后，对0.4 m 和1.2 m核孔膜不能形成有效封堵，降低过膜压力也不能改善其封堵性能。LPS经剪切降解后对1.2 m的核孔膜不能形成有效封堵，但对0.4 m的核孔膜能形成有效封堵；降低过膜压力能够增大对1.2 m核孔膜的封堵性能。LPS中交联聚合物线团(LPC)尺寸变小及HPAM与AlCit之间交联点的破坏分别是热氧化和剪切降解造成封堵性能下降的原因。

THE EFFECT OF THERMO-OXIDIZING AND SHEAR STABILITIES OF LINKED POLYMER SOLUTION ON ITS PLUGGING EFFICIENCY

The effects of thermo-oxidizing and shear stabilities of linked polymer solution (LPS) comprising of low concentration and high relative molecular mass partially hydrolyzed polyacrylamide ( HPAM) and aluminum citrate ( AlCit) on its plugging efficiency were experimentally determined by methods of nuclear pore membrane and dynamic light scattering (DLS), the reason of which was discussed.The results indicated that the LPS formed by HPAM and AlCit could not plug 0.4 and 1.2 μm nuclear pore membranes efficiently after thermo-oxidizing degradation at 90℃ for 24 h.Moreover, the plugging properties of LPS after thermo-oxidizing degradation were still not improved although the filtration pressure was lower.Also, LPS after shear degradation could not plug 1.2 μm nuclear pore membrane efficiently, but could plug 0.4 μm nuclear pore membrane efficiently.Besides, it had better plugging efficiency for 1.2 μm nuclear pore membrane even the filtration pressure dropped.The reason why the plugging efficiency of LPS declined after shear and thermo-oxidizing degradations was the size shrinkage of linked polymer coils (LPC) and the damage of cross-linked points between HPAM and AlCit by thermo-oxidizing degradation.