纤维素纳米晶杂化压裂液的流变性能

Rheological Properties of Nano Hybrid Cellulose Fracturing Fluid

易辉永 王世彬 李帅帅 刘城成

YI Huiyong WANG Shibin LI Shuaishuai LIU Chengcheng

针对目前纤维素压裂液存在黏度低、耐温性能差、携砂困难等技术难题，将纤维素经硫酸水解后得到的纤 维素纳米晶（CNCs）加入纤维素压裂液中，制得纳米杂化型纤维素纳米压裂液（简称纤维素纳米压裂液）。优选 了三乙醇胺与正丁醇锆复配交联剂与CNCs加量，用流变仪模拟了纤维素纳米压裂液冻胶在管道中的剪切过程， 研究了剪切速率、温度对纤维素纳米压裂液冻胶流变性能的影响。结果表明，在纤维素压裂液冻胶中，加入 1000 mg/L的CNCs可显著提高压裂液黏度。复配交联剂加量为0.4%时，纤维素纳米压裂液冻胶在25 ℃、170 s-1 下剪切稳定后的黏度可达600 mPa·s，比空白压裂液冻胶增黏160 mPa·s；120 ℃、170 s-1 下剪切60 min后的黏度 可达170 mPa·s，增黏70 mPa·s。CNCs可显著提高纤维素压裂液的携砂性能，在25 ℃下纤维素纳米压裂液冻胶 的弹性模量是空白压裂液冻胶的2倍。CNCs分散在纤维素网格中，作为核点有效提升了网格的抗剪切性能和 耐温性能。

In view of the technical problems such as low viscosity，poor temperature resistance and difficulty in carrying sand in cellulose fracturing fluid，nano hybrid cellulose fracturing fluid（cellulose nano fracturing fluid for short）was prepared by adding cellulose nanocrystals （CNCs） into cellulose fracturing fluid. The dosages of compound crosslinking agent composed of triethanolamine and zirconium butanol and CNCs were optimized. The shear process of cellulose nano fracturing fluid gel in pipeline was simulated by rheometer. The effects of shear rate and temperature on the rheological properties of cellulose nano fracturing fluid gel were studied. The results showed that adding 1000 mg/L CNCs into cellulose fracturing fluid gel could significantly improve the viscosity of fracturing fluid. When the amount of compound crosslinking agent was 0.4%，the viscosity of cellulose nano fracturing fluid gel could reach 600 mPa· s at 25 ℃ and 170 s-1，which was higher than that of blank fracturing fluid gel by 160 mPa· s. After shearing at 120 ℃ and 170 s-1 for 60 min，the viscosity could reach 170 mPa· s and the viscosity increment was 70 mPa· s. CNCs could significantly improve the sand carrying capacity of cellulose fracturing fluid gel. At 25 ℃，the elastic modulus of cellulose nano fracturing fluid was twice bigger than that of blank fracturing fluid gel. CNCs dispersed in the cellulose grid，which could effectively improve the shear resistance and temperature resistance.

10.19346/j.cnki.1000-4092.2021.02.007