Fe2+对聚合物的影响及其处理方法研究

Effect of Fe2+ on the apparent viscosity of polymer solution and controlling methods

关键词:  聚丙烯酰胺  降解作用  表观黏度  除铁 

Key words:  polyacrylamide  degradation  apparent viscosity  iron removal

摘要:

研究了配聚水中Fe²⁺的浓度对HPAM溶液黏度的影响机理,实验结果表明,随着溶液中Fe²⁺浓度增大,聚合物的相对分子质量和溶液的黏度呈下降趋势；当ρ(Fe²⁺)为0～0.5 mg/L时,HPAM的相对分子质量、黏度随Fe²⁺浓度的增加而大幅度下降；当ρ(Fe²⁺)超过0.5 mg/L时,下降趋势变缓；同时,原子力显微镜照片(AFM)显示, 含ρ(Fe²⁺)0.5 mg/L的聚合物溶液的网状结构也受到较大的破坏。为确保聚合物溶液的黏度,配聚水中ρ(Fe²⁺)应控制在0.5 mg/L以下,采用自然曝氧法、化学络合法和锰砂接触过滤法都可以达到除铁效果,其中以化学除铁法最为简单有效；使用高效除铁络合剂BHCT-1,加药质量浓度只需300 mg/L就可以取得良好的除铁效果,海上注聚油田现场应用效果良好,聚合物溶液黏度提高20%以上。 

Abstract:

The influences of Fe²⁺ on the apparent viscosity of polymer solution have been studied in this paper, and the results showed that a small amount of Fe²⁺ would make the polymer degraded severely. HPAM polymer molecular weight and viscosity declined dramatically with the increasing of CFe²⁺ among the 0～0.5 mg/L, and declined slowly when the CFe²⁺ above a concentration of 0.5mg/L. The AFM photos also showed that polymer network structure was destroyed largely. In order to ensure the polymer viscosity, the contents of Fe²⁺ in preparation water should not exceed to the concentration of 0.5 mg/L. There are several controlling measures used to remove Fe²⁺ in preparation water, such as oxygen exposure, chemical complex method and manganese sand filtration. Chemical complex method is the most simple and effective one among them. The high effective iron removal reagent BHCT-1 with a concentration of 300 mg/L showed a good effect to remove Fe²⁺. For example, it was applied in offshore polymer flooding oilfield, and the viscosity of polymer solution would be increased by more than 20%.