聚丙烯酰胺水溶液粘弹性研究

Studies on Viscoelasticity of Aqueous Hydrolyzed Polyacrylamide Solutions

在45℃下测定了水解度相近(26.4%～27.4%)、分子量不同(7.0×106,1.1×107和1.7×107)的3种商品HPAM水溶液的动态粘弹性参数并讨论了在驱油中的作用。在振荡频率0.1～100s-1范围,浓度1.2g/L的3种聚合物溶液的G′和G″曲线均相交,交点对应的频率随分子量增大而减小,在交点以下G″>G′,而在交点以上G′>G″。对于分子量较高的2种聚合物溶液,在频率1.256s-1时,G′和G″随聚合物浓度的增大(0.2～2.0g/L)而增大;浓度一定时(2.0g/L)随加入的NaCl浓度的增大(0～9.0g/L)而剧烈减小,随加入的表面活性剂SDBS浓度的增大(0～10g/L)而有一定幅度的减小;在温度10～55℃区间测得的2.0g/L聚合物溶液的G′～T和G″～T曲线,在温度～35℃时出现最大值。加入5.0g/LNaOH或NaCl使浓度1.2g/L的最高分子量聚合物溶液的线性粘弹性区间变窄,损耗角增大。图6参1表8。

The characteristics of viscoelasticity of aqueous polymer solutions are determined at 45℃ for 3 commercial HPAMs of similar hydrolysis degree, 26.4—27.4%, but different molar mass, 7.0×10~6, 1.1×10~7, and 1.7×10~7 and their functions in oil displacement are discussed. In oscillation frequency range 0.1—100 s^(-1), the G′ and the G″ curves of these polymer solution intersect at higher frequency when the molar mass is lower and G″>G′ below and G′>G″ above the intersect. For the 2 HPAMs of higher molar mass at frequency 1.256 s^(-1), G′ and G″ increase with increasing solution concentration (0.2—2.0 g/L); decrease significantly with increasing concentration of NaCl added (0—9.0 g/L) and moderately with concentration of surfactant SDBS added (0—10 g/L) when polymer concentration being of 2.0 g/L and G′-T and G″-T relationships at temperature range 10—55℃ go through maxima located at ～35℃.