一种疏水缔合聚合物稠化剂的合成及压裂液性能评价

Synthesis of a hydrophobically associating polymer thickening agent and evaluation of the fracturing fluid properties

以AM、AMPS和阳离子疏水单体MD-18为单体,采用水溶液自由基聚合法合成了疏水缔合聚合物压裂液稠化剂HAPAM-18。研究了HAPAM-18的增黏性能、与表面活性剂的相互作用以及压裂液体系的相关性能。结果表明,HAPAM-18的表观黏度随质量浓度增加而增大,临界缔合浓度为0.15g/L;HAPAM-18与表面活性剂的相互作用符合三阶段模型,且SDBS与HAPAM-18的相互作用强于CTAB;ρ(HAPAM-18)0.6g/L+c(SDBS)0.5mmol/L+ρ(KCl)2g/L配制的压裂液体系的耐温性能达到101℃。耐剪切性实验和动态频率扫描表明,该压裂液体系具有良好的耐剪切性和黏弹性;过硫酸铵能使压裂液彻底破胶,破胶液残渣含量低至未检出,该压裂液是一种清洁压裂液。

A hydrophobically associating polymer thickening agent HAPAM-18 for fracturing fluid was synthesized by the aqueous solution free-radical copolymerization of AM, AMPS and a cationic hydrophobic monomer MD-18. The thickening ability and interactions with surfactant of HMPAM-18 were studied as well as the fracturing fluid properties. Result shows that the apparent viscosity of HAMPAM-18 solution increased with increasing concentration and its critical aggregation concentra- tion is 0.15 g/L. The interactions between HAPAM-18 and surfactants fitted the three stage model and the interactions between HAPAM-18 and SDBS is more intensive than that with CTAB. The frac- turing fluid system composed of 0.6 g/L HAPAM-18 ＋ 0.5 mmol/L SDBS ＋ 2 g/L KC1 reached a temperature resistance of 101 ℃ and showed good shear resistance and viscoelasticity. The fracturing fluid system can be completely broken with unmeasurable insoluble residuals by ammonium persulfate as the gel-breaker which means this system can be taken as clean fracturing fluid.