四元聚合物溶液及其压裂液流变性能

Rheological Properties of Quadripolymer Solution and Its Fracturing Fluid

为丰富凝胶压裂液体系,以新型四元聚合物[甲基丙烯酸(MAA)/2-丙烯酰胺基-2-甲基丙磺酸(AMPS)/N,N-二甲基丙烯酰胺(DMAM)/对苯乙烯磺酸钠(SSS)]为稠化剂,与有机锆交联剂交联,研究了不同浓度四元聚合物溶液和交联过程中的流变性,考察了剪切速率和温度对交联过程中黏度-时间关系的影响;并研究了交联凝胶破胶过程中的流变性,考察了破胶剂加量和温度对破胶过程中复模量-时间关系的影响。结果表明,170 s^(-1)下,聚合物溶液黏度随聚合物质量分数的增加而增大,0.6%聚合物溶液的稳态黏度为107.7 mPa·s,流动曲线符合Cross本构方程。交联体系黏度随剪切速率增加和温度升高而降低,黏度随时间变化的曲线可用4-参数交联过程流变动力学模型描述。在实验范围内,破胶剂用量越多、温度越高,凝胶破胶效果越好。4-参数破胶过程流变动力学模型可用于描述破胶过程中复模量随时间的变化曲线。图9表4参24。

In order to enrich the gel fracturing fluid system,the new quadripolymer synthesized by methacrylic acid(MAA),2-acrylamido-2-methylpropane sulfonic acid(AMPS),N,N-dimethylacrylamide(DMAM)and sodium p-styrenesulfonate(SSS)was used as a thickener,and the organic zirconium crosslinking agent was used to crosslink it.The rheological properties of the quadripolymer solution at different concentrations and their cross-linking processes were studied.The effects of shear rate and temperature on the relationship between viscosity and time during cross-linking process were investigated.The rheological properties of polymer crosslinked gel’s breaking processes were studied too.The effects of breaker dosage and temperature on the relationship between complex modulus and time during gel breaking process were investigated.The results showed that the viscosity of polymer solution increased with increasing polymer mass faction at 170 s^(-1).The steady-state viscosity of 0.6%polymer solution was 107.7 mPa·s,and the flow curve was conformed to the Cross constitutive equation.The viscosity of cross-linking system decreased with increasing shear rate and temperature.The curve of viscosity varying with time in cross-linking process could be described by 4-parameter cross-linking process model.In the experimental range,the more dosage of breaker and the higher temperature,the better effect of gel breaking process was.The rheological kinetic model of 4-parameter gel breaking process could be used to describe the curve of complex modulus varying with time in gel breaking process.