地层水压裂液体系研制

为了缓解川西气田地层水大量产出带来的环境保护压力和成本压力,对川西地区地层水的类型、成分以及矿化度深入分析的基础上,分别采用低矿化度地层水和高矿化度地层水配制成功了地层水瓜胶压裂液体系和地层水降阻水体系。地层水瓜胶压裂液体系在45℃下剪切90 min黏度可达100 m Pa·s以上,破胶液表面张力为27.66 m N/m,防膨率为87.5%,伤害率为26.5%;通过优选耐盐降阻剂,配制出一种地层水降阻水体系,其降阻率可达69%~71%。地层水瓜胶压裂液在SF38-2井和SF38-4井成功应用,增产效果明显;地层水降阻水体系在X502井非常规气藏体积压裂施工中得到成功应用。2套地层水压裂液体系性能均与清水压裂液性能相当,具有良好的推广应用前景。

Study on Fracturing Fluid Prepared with Formation Water

Formation waters of different salinities were studied for use in the preparation of fracturing fluids for the sake of environment protection and cost control in gas fields, west Sichuan. The guar gum fracturing fluid prepared with formation water had viscosity of 100 mPa·s after shearing 90 min at 45℃, surface tension of 27.66 mN/m, rate of swelling reduction of 87.5%, rate of permeability impairment of only 26.5%. Using salt-resistant friction reducer, the slick water prepared with formation water reduced flow friction by 69%-71%. The formation water fracturing fluid has been used in the Well SF38-2 and the Well SF38-4 with good results. The slick water was successfully used in the SRV fracturing operation in the Well X502, a nonconventional gas well.