自破胶中低温清洁压裂液制备及性能评价

Preparation and Performance Evaluation of Self-breaking Clear Fracturing Fluid for Low-medium Temperature Reservoirs

左建平 马广华 喻翔 苏海成 魏振强

ZUO Jianping MAGuanghua YU Xiang SU Haicheng WEI Zhenqiang

为获得可用于中低温储层的阳离子清洁压裂液，以二元阳离子黏弹性表面活性剂VES-LT为主剂、水杨酸钠为胶束促进剂、氯化钾为黏土稳定剂，制备了VES-LT清洁压裂液。对该清洁压裂液的黏温特性、悬砂性能、破胶性能以及对支撑剂填层渗透率的影响进行了评价。结果表明，增加VES-LT的加量可以提高压裂液的黏度；VES-LT 清洁压裂液体系抗温可达110℃，温度对压裂液黏度的影响小于交联胍胶压裂液。砂比为20%时，VES-LT清洁压裂液的静态悬砂能力好于黏度相近的常规胍胶压裂液。该清洁压裂液体系无需加入破胶剂，遇油或水自动破胶，破胶液黏度为2.4 mPa·s。VES-LT清洁压裂液对支撑剂填层渗透率的损害小于常规胍胶压裂液体系，可用于中低温低渗透非常规油气储层改造。图5 表1 参21

In order to obtain one type of clear fracturing fluid that could be used for low-medium temperature reservoirs，VES-LT fracturing fluid was prepared by using binary cationic viscoelastic surfactant VES-LT as main agent，sodium salicylate as micelle co-agent and potassium chloride as clay stabilizer. The rheological behaviors，proppant-suspension property，breaking property and the effect on permeability of proppant pack layer were evaluated. The results showed that the viscosity of fracturing fluid increased with increasing concentration of VES-LT. The VES-LT clean fracturing fluid had good resistance of high temperature（110℃）. The effect of temperature on the viscosity of VES-LT clear fracturing fluid was smaller than that of cross-linked guar gum fracturing fluid. The static proppant-suspension property of VES-LT clear fracturing fluid was much better than that of conventional guar gum fracturing fluid with similar viscosity when the proppant concentration was 20%. This clean VES-LT fracturing fluid system didn’t need gel breaker. Both oil and water could break the gel down and the viscosity of broken fluid was 2.4 mPa·s. The damage of VES-LT clear fracturing fluid to the permeability of proppant pack layer was far less than that of conventional guar gum fracturing fluid system. This clear VES-LT fracturing fluid system could be used for low-medium temperature stimulation of low permeability unconventional reservoirs.

10.19346/j.cnki.1000-4092.2018.01.007