高盐油藏新型生物聚合物的增黏能力和驱油效果

Viscosifying ability and oil displacement efficiency of new biopolymer in high salinity reservoir

利用生物发酵提纯制备新型生物聚合物BZZF,研究在高盐矿化水中BZZF的增黏性能,并通过与表面活性剂复配构建具有增黏能力和降低油水界面张力的二元复合驱油体系。结果表明:在高盐矿化水中,生物聚合物BZZF表现出具有比常规聚合物HPAM、疏水缔合聚合物HPOC和黄胞胶XG更优异的增黏效果,在含NaCl 130 g/L、MgCl_210 g/L和CaCl_245 g/L的极高盐质量浓度矿化水中1 000 mg/L BZZF的黏度可达到93. 3 m Pa·s;甜菜碱两性型表面活性剂GS、非离子型表面活性剂TS、阴-非离子两性型表面活性剂APS的加入不仅可以提高生物聚合物BZZF在高盐矿化水中的黏度,而且可以使油水界面张力降低到10-2m N/m量级以下;由于在高盐矿化水中具有良好的增黏效果,含生物聚合物BZZF的化学驱油体系在高盐矿化水中具有较好的驱油效果。

One new biopolymer named BZZF was prepared by biological fermentation and purification.The viscosifying ability of BZZF in high salinity mineralized water was investigated.And the polymer-surfactant flooding systems with viscosifying and reducing oil/water interfacial tension properties were formed through adding surfactants.It is found that biopolymer BZZF shows better viscosifying ability than conventional polymer HPAM,hydrophobically associating polymer HPOC and Xanthan gum XG in high salinity mineralized water.The viscosity of 1000 mg/L BZZF can reach 93.3 mPa·s in extremely high salinity mineralized water containing NaCl 130 g/L,MgCl2 10 g/L and CaCl 2 45 g/L.The addition of betaine amphoteric surfactant GS,nonionic surfactants TS and negative ionic-nonionic amphoteric surfactant APS can not only improve the viscosity of biopolymer BZZF,but also reduce the oil/water interfacial tension down to less than 10^-2 mN·in high salinity mineralized water.The chemical flooding system containing biopolymer BZZF presents good oil displacement efficiency because of its good viscosifying ability in high salinity mineralized water.