聚丙烯酰胺相对分子质量对冻胶稳定性的影响研究

Effect of Polyacrylamide Molecular Weight on Gel Stability

聚丙烯酰胺冻胶堵剂是目前较为常用堵水调剖剂,现场应用存在聚合物相对分子质量过大、支链过多,导致过炮眼剪切严重、交联效果差,影响堵调效果。对聚丙烯酰胺相对分子质量对冻胶稳定性的影响进行了室内试验研究。用现场污水配制不同浓度的聚丙烯酰胺溶液,与酚醛交联剂交联,测试成胶前后黏度变化、成胶强度、热稳定性、抗剪切性及封堵性能。结果表明,聚合物相对分子质量为800万~1 500万,聚合物初始黏度低,成胶后强度高,热稳定性好,抗剪切能力高,封堵效果好。

Polyacrylamide gel is one of the most frequently used water blocking agents. Because of the high molecular weight and too much branched chains of the polymer used in-situ,the gel is easily to be sheared by the perforated pores and the crosslinked action is weak causing bad blocking effect. Indoor experiments are done to study the influence of polyacrylamide molecular weight on gel stability. In-situ drainage water is used to prepare polymer gel of different molecular weight,and then phenolic aldehyde is added as cross linker.Properties such as viscosity,intensity,stability and so on,are tested and results show that when the molecular weight is about（ 800-1 500） × 10^4,the initial viscosity is low and cross linking intensity is high with high temperature stability,high shearing resistance and high blocking effect.