为满足高矿化度复杂水配液的需求,对矿化度均为20×10⁴ mg/L的KCl、CaCl₂、MgCl₂以及模拟海水中部分水解聚丙烯酰胺(HPAM)的流变性进行了研究,将其与有机锆进行交联,研制了可耐超高矿化度的HPAM凝胶压裂液新体系,并对其交联过程进行深入研究。结果表明,高矿化度盐溶液会降低HPAM的稳态黏度与黏弹性,其中Ca²⁺的影响最为显著;在自来水、KCl溶液、模拟海水、MgCl₂溶液、CaCl₂溶液中HPAM凝胶强度依次下降;HPAM恒温小振幅振荡交联过程可用四参数流变动力学方程描述;升温交联过程可以分为缓速交联与快速交联两个阶段;大振幅振荡交联过程表明过高的剪切应变不利于提高凝胶的强度,Lissajous曲线显示HPAM在100%与500%剪切应变下交联过程分别为线性流变行为与非线性流变行为。

In order to meet the demand for complex water blending fluid with high mineralization,the rheological properties of partially hydrolyzed polyacrylamide (HPAM) in KCl,CaCl₂,MgCl₂,and simulated seawater each with a mineralization of 20×10⁴ mg·L^-1 are studied.HPAM is cross-linked with organic zirconium to develop a novel HPAM gel fracturing fluid system that can resist ultra-high mineralization,and the cross-linking process is also studied in depth.It is demonstrated that the salt solution with a high mineralization decreases the steady-state viscosity and viscoelasticity of HPAM,among which Ca²⁺ solution has the most significant impact.The gel strength of HPAM in tap water,KCl solution,simulated seawater,MgCl₂ solution,and CaCl₂ solution declines sequentially.The cross-linking process of HPAM at constant temperature and small amplitude oscillation can be described by a four-parameter rheology-kinetics equation.The temperature-rising cross-linking process can be divided into two stages:slow cross-linking and fast cross-linking.It is shown by the large-amplitude oscillatory cross-linking process that too high shear strain is not conducive to the improvement of gel strength.Lissajous curves indicate that the cross-linking process of HPAM at 100% and 500% of shear strain is linear and nonlinear rheological behavior,respectively.This study is expected to enrich the fracturing fluid system under ultra-high mineralization.