耐高温低伤害清洁水性稠化剂的制备及性能

Preparation and properties of a heat-resistant and clean water-based thickener

摘要:

针对高温储层压裂需求，以丙烯酰胺（AM）、丙烯酸（AA）、十八烷基二甲基烯丙基氯化铵（ODAAC）和十八烷基甲基丙烯酸酯（SMA）为原料制备了一种疏水缔合聚合物（AAOS），再使用低分子醇（乙二醇、丙三醇、正丙醇）、表面活性剂（椰子油脂肪酸二乙醇酰胺和十二烷基硫酸钠）和AAOS配制开发一种“自交联”耐高温清洁水性稠化剂（FPM-1）。SEM结果表明，质量分数为0.30 %的FPM-1水溶液能显著增强AAOS聚合物分子间的疏水缔合交联作用，增大聚合物的流体力学体积。通过对FPM-1的溶解性、表观黏度、耐盐性、流变学测试表明，FPM-1溶液为高黏弹性流体，悬砂性能好；质量分数为0.27 %的AAOS在水中的溶解时间为7 min，最终黏度为90 mPa·s，质量分数为0.60 %的FPM-1（具有等效聚合物含量）在水中的溶解时间仅需3 min，且最终黏度为165 mPa·s，表明FPM-1体系能显著提高聚合物的黏度和溶解速度。在90℃，170 s-1条件下剪切1 h后，质量分数为0.27 %的AAOS水溶液的黏度为51 mPa·s，质量分数为0.60 %的FPM-1水溶液黏度为77 mPa·s；质量分数为1.40 %的FPM-1水溶液在180℃，170 s-1条件下剪切1 h，最终黏度为53 mPa·s；质量分数为0.60 %的FPM-1在5×104 mg/L矿化度盐水中黏度保持率为60 %，因此，FPM-1水溶液具有优异的耐盐、耐高温、耐剪切性能。通过对破胶液的表/界面张力测试表明，FPM-1体系破胶液具有低的表/界面张力，有利于破胶液的返排和回收再利用。

Abstract:

In order to meet the needs of high temperature reservoir fracturing, a hydrophobically associating polymer ( AAOS ) was synthesized by acrylamide ( AM ), acrylic acid ( AA ), octadecyl dimethyl allyl ammonium chloride ( ODAAC ) and octadecyl methacrylate ( SMA ), then, a new “self-crosslinking” high temperature resistant water-based liquid thickener ( FPM-1 ) was developed by using low molecular alcohol (ethylene glycol, glycerol, n-propanol), surfactant (coconut diethanol amide and lauryl sodium sulfate) and AAOS. SEM analysis showed that the mass fraction of 0.30 % FPM-1 aqueous solution could significantly increase the hydrophobic association crosslinking between AAOS polymer molecules and increase the hydrodynamic volume of the polymer. The solubility, apparent viscosity, salt tolerance and rheological properties of FPM-1 were tested. The results showed that FPM-1 solution was a high viscoelastic fluid with good sand suspension performance. The dissolution time of the mass fraction of 0.27 % AAOS was 7 min in water and the final viscosity was 90 mPa · s. The dissolution time of the mass fraction of 0.60 % FPM-1 with the same effective polymer content was only 3 min in water and the final viscosity was 165 mPa · s, indicating that the FPM-1 system could significantly improve the viscosity and dissolution rate of the polymer. After shearing at 90 °C, 170 s-1 for 1 h, the viscosity of the mass fraction of 0.27 % AAOS aqueous solution was 51 mPa · s, the viscosity of the mass fraction of 0.60 % FPM-1 aqueous solution was 77 mPa · s, and the viscosity of the mass fraction of 1.40 % FPM-1 aqueous solution was 53 mPa · s after shearing at 180 °C, 170 s-1 for 1 h. The viscosity retention rate of the mass fraction of 0.60 % FPM-1 in 5 × 104 mg / L salinity brine was 60 %. FPM-1 solution has excellent salt resistance, high temperature resistance and shear resistance. The surface/interfacial tension test showed that the FPM-1 system had low surface/interfacial tension, which was conducive to the flowback and recycling of the fracturing fluid breaking liquid.