气田中浅层地层水压裂液体系研究

摘要

For the sake of environment protection,shallow formation waters were studied for the preparation of guar gum fracturing fluids in gas fields,west Sichuan.The fracturing fluid prepared with formation water had viscosity of 100 mPa·s after shearing 60 min(1 70 s-1 )at 45 ℃,rate of permeability impairment of only 23.86%,surface tension of 27.82 mN/m, rate of swelling reduction of 87.5%,residue content of 5 18 mg/L.The formation water fracturing fluids were successfully used in SF38-2 and SF38-4,which respectively improved natural gas production of 1.14 × 10 4 m3/d and 1.68 × 10 4 m3/d.This technology enabled the reuse of formation sewage water in gas fields.%为了降低川西气田地层产出水带来的环境压力,在地层水的水质分析基础上,研制了适用于川西中浅层气藏的地层水瓜胶压裂液体系。该地层水压裂液体系在45℃、170 s-1条件下剪切60 min,黏度可保持在100 mPa·s 左右,伤害率23.86%,破胶液表面张力27.82 mN/m,防膨率87.5%,残渣质量浓度518 mg/L,具有破胶彻底、流变性好等优点。在什邡38-2井和什邡38-4井的现场试验取得了显著的增产效果,分别获得天然气产量达1.14×104 m3/d和1.68×104 m3/d,实现了气田地层产出水的重复利用。