耐高温海水基压裂液聚合物稠化剂流变性能

Rheological properties of polymer thickener for high-temperature resistant seawater-based fracturing fluid

为明确聚合物稠化剂分子量、功能单体种类及含量等参数对海水基压裂液流变性能的影响,选用分别具有强电解质单体2-丙烯酰胺-2甲基丙磺酸(AMPS)或可抑制酰胺基水解单体N-乙烯基吡咯烷酮(NVP)的超高分子量聚合物,研究了聚合物溶液的流变性能。对具有超高分子量及不同AMPS含量的5种聚合物进行了聚合物交联冻胶耐温耐剪切性能研究。实验结果表明,具有超高分子量及较低AMPS含量的聚合物黏弹性更好,具有超高分子量及高AMPS含量的聚合物在高温下耐剪切性能更好,具有超高分子量及NVP基团的聚合物在海水中增稠能力更好,具有高AMPS含量的聚合物耐温耐剪切性能更好;具有超高分子量(分子量不低于2×10^(7))、适宜的水解度(20%~23%)、低AMPS含量(3%~8%(w))的聚合物,更适于作为耐高温海水基压裂液稠化剂。

In order to determine the effects of molecular weight of polymer thickener,type and content of functional monomers on the rheological properties of seawater-based fracturing fluid,ultra-high molecular weight polymers with strong electrolyte monomer 2-acrylamide-2-methylpropyl sulfonic acid(AMPS)or amide hydrolysis inhibition monomer N-vinylpyrrolidone(NVP)were selected to study the rheological properties of polymer solution.A study on the temperature and shear resistance of polymer crosslinked gel was conducted on 5 polymers with ultra-high molecular weight and different AMPS contents.The experimental results show that polymers with ultra-high molecular weight and low AMPS content have better viscoelasticity,polymers with ultra-high molecular weight and high AMPS content have better shear resistance at high temperatures,polymers with ultra-high molecular weight and NVP groups have better thickening ability in seawater,and polymers with high AMPS content have better temperature and shear resistance.Polymers with ultra-high molecular weight(molecular weight no less than 2×10^(7)),suitable hydrolysis degree(20%-23%),low AMPS content(3%-8%(w))are more suitable as thickeners for high temperature resistant seawater-based fracturing fluid.