可变粘压裂液研究及在深煤层中应用

Study on Variable Viscosity Fracturing Fluid and Its Application in Deep Coal Seam

针对深煤层压裂开发需要,研发一套可变粘压裂液体系,通过粘度、降阻率、表面张力、界面张力等指标优选构建了低粘-中粘-高粘滑溜水体系,并对体系滤失性能、破胶性能和岩心伤害性能进行了评价。实验结果表明:随着体系粘度增加,降阻率先增加后降低;高粘度有助于降低滤失。通过调节破胶剂用量实现破胶可控,对煤岩具有较小的岩心伤害率。配合体积改造压裂工艺,可有效助力深煤层开发。优选的可变粘压裂液具有较好的推广和应用前景。

According to the needs of deep coal seam fracturing development,a set of variable viscosity fracturing fluid system was developed,and the low viscosity,medium viscosity and high viscosity slick water system was optimized through viscosity,drag reduction rate,surface tension,interfacial tension and other indicators,and the filtration performance,gel breaking performance and core damage performance of the system were evaluated.The experimental results showed that with the increase of the viscosity of the system,the resistance reduction first increases and then decreased,high viscosity helped to reduce filtration loss.The gel breaker could be controlled by adjusting the amount of gel breaker,and had a small core damage rate to coal and rock.Combined with volume modification fracturing technology,it could effectively assist the development of deep coal seams.The selected variable viscosity fracturing fluid had good prospects for popularization and application.