为了降低超低渗透油田的注水压力，增加注水量，研制出由质量浓度为320～850 mg/L 的双子表 面活性剂G12-3、质量浓度为60～200 mg/L 的防膨剂NNR、质量浓度为16～50 mg/L 的阻垢剂YJ 以 及质量浓度为4～20 mg/L 的铁离子稳定剂QA 组成的降压增注体系。当降压增注体系溶液的质量浓 度为400～1 200 mg/L 时，油水界面张力降至10-3 mN/m，防膨率为81.2%～89.3%，Ca2+，Ba2+ 和Fe3+ 的 阻垢率分别为84.7%，83.5% 和81.7%；降压增注体系溶液能够使亲油的云母表面向弱亲水转变；从油水 相对渗透率曲线可看出，降压增注体系溶液能够改善地层中油水的渗流能力。现场试验表明，降压增注 体系溶液使欠注井（T214-16 井）的注入压力平均降低了3.5 MPa，且能够按照配注量注水，有效期达6 个月以上，在该区取得了较好的应用效果。

In order to reduce injection pressure and increase water injection in ultra-low permeability oilfield, a system of depressurization and stimulation of injection well was developed. It is constituted by 320～850 mg/L gemini surfactant G12-3, 60～200 mg/L antiswelling agent NNR, 16～50 mg/L inhibition agent YJ and 4～20 mg/L ferric ion stabilizer QA. The interfacial activity, antiswelling performance, inhibition ability, and reverse wetting ability of this system were investigated under various conditions. When the mass concentration of the depressurization and stimulation of injection well system solution was 400～1 200 mg/L, the interfacial tension was reduced to 10-3 mN/m, the antiswelling rate is 81.2%～89.3%, and the inhibition rate was 84.7%, 83.5% and 81.7% for Ca2+, Ba2+ and Fe3+ respectively. With the increase of mass concentration of this system, mica surface wettability turned to weak water wettability, and oil-water relative permeability curve also shows that the system could improve the flow ability of formation fluid. At last, field test shows that the system made the injection pressure of injection well T214-16 reduced about 3.5 MPa, and the term of the validity of this measure was more than 6 months. It attained good application effect in this area.