盐对聚丙烯酰胺黏度的影响评价

Effect Evaluation of Salt on Polyacrylamide Viscosity

聚丙烯酰胺的抗盐、抗剪切性能较差,且有一定的化学降解性能,因此,聚合物(PAM)驱油剂的耐盐、增黏问题已经成为三次采油技术中极具挑战性的研究课题。影响溶液黏度的因素较多,本文主要研究几种离子对聚丙烯酰胺黏度的影响。以分子量500～700万的聚丙烯酰胺为原料,在一定温度下,探究不同的放置时间及不同的离子浓度下所形成的聚丙烯酰胺水溶液的黏度,通过测量其不同情况下的黏度,研究离子对聚丙烯酰胺的降黏效果。实验结果表明,聚合物的浓度越高,聚丙烯酰胺水溶液的黏度越大;聚合物浓度一定时,加入一定的盐,水溶液体系的黏度降低,且随着盐浓度的增加,体系黏度减小得更为明显。当盐的量达到某一程度,体系的黏度不再减小。此类盐的离子中,钙、镁、钡等二价离子的降黏效果较为明显,对聚丙烯酰胺水溶液黏度的影响依次为Ca^(2+)>Mg^(2+)>Ba^(2+)>K^+>Na^+。

Polyacrylamide(PAM)salt resistance and shear resistance were poor.And it had certain chemical degradation performance.Therefore,the problem of salt resistance and viscosity enhancement of polymer(PAM)flooding agent had become a very challenging research topic in tertiary oil recovery technology.The solution viscosity was affected by many factors.This paper mainly studied the influence of several neutral salts on the viscosity of polyacrylamide.Polyacrylamide with a molecular weight of 5~7 million was used as raw material to investigate the viscosity of aqueous solution of polyacrylamide formed under different standing time and different neutral salt ion concentration at a certain temperature.The viscosity reduction effect of neutral salt ions on polyacrylamide was studied by measuring the viscosity of polyacrylamide under different conditions.The experimental results showed that the higher the polymer concentration,the greater the viscosity of the polyacrylamide aqueous solution.When the concentration of polymer was enough,the viscosity of aqueous solution decreased with the addition of certain neutral salts,and with the increase of the concentration of neutral salts,the viscosity of the system decreased more obviously.When the amount of neutral salt reached a certain level,the viscosity of the system would not decrease.Among these neutral salts,Ca,Mg,Ba and other divalent ions had obvious effect on reducing the viscosity of polyacrylamide aqueous solution.The order of their effects on the viscosity of polyacrylamide aqueous solution was Ca^2+>Mg^2+>Ba^2+>K^+>Na^+.