两性/阴离子表面活性剂清洁压裂液性能评价

Performance Evaluation of Zwitterionic/Anionic Mixed Surfactant Clean Fracturing Fluid

夏亮亮 周明 张灵 加文君 曹静

XIA Liangliang，ZHOU Ming，ZHANG Ling ，JIA Wenjun ，CAO Jing

为解决阳离子型表面活性剂压裂液的性能缺陷，采用两性离子型表面活性剂和阴离子型表面活性剂制备出了清洁压裂液，考察了其性能特征。研究结果表明，两性/阴离子表面活性剂清洁压裂液黏度随KCl 加量的增大先增加后减小，随SDS 加量的增大而增加。组成为2.24% 甜菜碱+ 0.9% 十二烷基硫酸钠（SDS ）+ 6.2% KCl 的两性/阴离子表面活性剂清洁压裂液在65℃、170 s-1下恒温剪切约40min，压裂液黏度保持在59.5 mPa·s 左右，耐温耐剪切性较好。在室温、55℃、65℃条件下，砂粒在压裂液中的沉降速率分别为0.02、0.14、0.51mm/s，携砂性较好。煤油加量为2% 时，压裂液快速破胶，破胶液黏度2.15mPa·s，表面及界面张力分别为26.542 和0.8562mN/m，无残渣。压裂液在天然岩心的滤失系数为5.6 × 10-4m/min1/2，滤失性较好。破胶液对岩心渗透率的伤害率为19.1%，比较适合于温度在65℃以内的地层。图4 表1 参10

Aimed at the defects of the cationic viscoelastic fracturing floodings, a zwitterionic/anionic mixed sufactant clean fracuring flooding was prepared and the relative properties were characterized. The viscoelastic surfactant fracturing fluid was made of 2.24% zwitterionic surfactant betaine，0.9% anionic surfactant SDS，6.2% KCl and deionized water. The result of performance evaluation indicated that the viscosity of fracturing fluid increased firstly and then decreased with increasing concentration of KCl，and that increased with increasing dosage of SDS. The apparent viscosity of fracturing fluid was about 59.5 mPa·s at 65℃and 170s-1 after shearing 40minutes，indicating good temperature resistance and shear resistance performance. The sedimentation rate of sands in fracturing fluid was 0.02，0.14and 0.51mm/s at room temperature，55℃and 65℃respectively ，indicating good sand-carrying performance. The viscosity of fracturing fluid decreased to 2.15mPa·s quickly when the dosage of kerosene was 2% ，the surface and interfacial tension of the breaker fluid was 26.542 and 0.8562mN/m respectively ，and there was no residue. The leak-off coefficient of fracturing fluid in natural core was 5.6 × 10-4m/min1/2 ，exhibiting a good filtration property. The damage rate ofbreaker fluid to the core permeability was19.1% ，and the fracturing fluid was suitable for the fracturing operation in the reservoirwithin 65℃.