适合低渗高盐油藏的表面活性剂复配体系及性能研究

Performance Evaluation of Mixed Surfactants for EOR in High Salinity and Low Permeability Reservoirs

宋官龙

SONG Guanlong

为获得适合长庆油田低渗高盐油藏使用的驱油体系，通过将石油磺酸盐阴离子表面活性剂CQPS和脂肪醇系列非离子表面活性剂ZFC-2复配，并加入醇类助剂ZJ-5，得到表面活性剂复配驱油体系YFFP-2，对其界面特性、乳化性能、吸附性能和提高采收率性能进行了研究。结果表明，YFFP-2复配体系的最佳配方为0.15% CQPS+0.05% ZFC-2+0.005% ZJ-5。在80℃、矿化度50 g/L的条件下，YFFP-2与脱水原油的界面张力为3.35×10-3 mN/m；YFFP-2乳状液静置15 h后的析水率约15%；在天然低渗（20×10-3 μm2）岩心上的动态吸附量为0.63 mg/g，远小于其在油砂、净砂上的静态吸附量（13.9、12.8 mg/g）；YFFP-2驱油的最终采收率为68.4%，采收率增幅为26.4%，提高采收率的作用优于CQPS。图6参14

In order to get an effective flooding system used in low permeability and high salinity reservoir in Changqing oilfield, a kind of mixed surfactants YFFP-2 was obtained through the mixture of petroleum sulfonate anionic surfactant CQPS and fatty alcohol series of nonionic surfactant ZFC-2 with the help of additive ZJ-5. The interface characteristic, emulsifying property, adsorption and EOR performance of the mixed surfactants were evaluated. The results showed that the best formula for the system was obtained as follows: 0.15% CQPS, 0.05% ZFC-2 and 0.005% ZJ-5. The interfacial tension between YFFP-2 and oil was 3.35×10-3 mN/m at the condition of 80℃ and salinity of 50 g/L. The drainage rate of YFFP-2 emulsion after placing 15 h was 15%. The dynamic adsorption in natural low permeability core (20×10-3 μm2) was 0.63 mg/g, which was much smaller than the static adsorption in the surface of oil sand and clean sand (13.9, 12.8 mg/g). The final oil recovery of YFFP-2 system was 68.4%, and the mixed surfactants flooding could improve the oil recovery by 26.4% on the basis of water flooding. The EOR effect of the mixed surfactants was better than that of CQPS.