耐高温低碳烃无水压裂液室内研究

摘要

Conventional water-free fracturing fluid can characterized by poor heat-resistance.Under such circumstances,water-free fracturing fluids based on low-carbon chain hydrocarbon pentane,phosphate surfactant (LPEA-1) and viscosity promoter (FS-1) were developed with desirable heat-resistant performances.In the concerned study,the properties of the fracturing fluid Frac-H were evaluated.The viscosity of the fracturing fluids is higher than 50 mPa·s after a continuous shearing of 120 min under temperature 130 ℃ and a shearing rate of 170 s-1 and it may have maximum viscosity after 180 s.No gel breaker is required during gel breaking processes.In addition,no residue was found in the fluids after gel breaking.The pentane-based Frac-H fracturing fluid may cause slightly higher damage to shale formations than to tight formations,but they are much less than those induced by water-based fracturing fluids.Research results showed that the pentane-based Frac-H fracturing fluid with pentane,phosphate surfactant and viscosity promoter can effectively meet the performance requirements towards frac fluid in unconventional reservoirs fracturing treatment.%针对目前国内低碳烃无水压裂液耐温能力差的问题,用戊烷、磷酸酯胶凝剂LPEA-1和黏度促进剂FS-1配制了耐高温低碳链烃无水压裂液(戊烷基Frac-H压裂液),并对其性能进行了初步评价.通过室内试验研究,确定戊烷基Frac-H压裂液的基本配方为95.8%戊烷+2.0%LPEA-1+2.2%FS-1,按此配制的压裂液在180 s后黏度达到最大;在温度为130 ℃、剪切速率为170 s-1条件下连续剪切120 min后的黏度大于50 mPa·s;破胶时不需加入破胶剂,且破胶液无残渣;戊烷基Frac-H压裂液对页岩储层的伤害稍大于致密性储层,但显著低于水基压裂液对页岩岩心的伤害.研究结果表明,用戊烷、磷酸酯和黏度促进剂配制的戊烷基Frac-H压裂液,可以满足非常规储层高温油气井压裂施工对压裂液性能的要求.