生化/NF技术处理低渗透油田回注水研究

渤南油田属低渗透油藏,目前回注水水质不合格,悬浮物、细菌等超标,钙镁离子含量高,结垢严重,引起注水量下降,注水压力上升.针对渤南油田污水水质情况及注水水质要求,开展了油田污水生化/NF处理实验研究.采用气浮、生物接触氧化结合膜过滤工艺,污水经处理后油质量浓度低于0.5 mg/L,SRB、悬浮物检测不出,钙镁离子质量浓度降至8 mg/L以下.在达到A1级标准基础上,有效解决了回注水结垢问题.

Treatment of the oily wastewater for the reinjection water in low permeability oilfields using biological and NF membrane treating technology

There are a lot of suspended substance,bacteria,calcium ion,magnesium ion,etc.in the produced water from the permeability reservoirs in Bonan oilfield,and therefore its quality cannot meet the strict requirement of the reinjection water.If the untreated produced water is used as the reinjection water,it will strictly scale the permeability reservoir,the quantity of injection water will decrease and injection pressure will increase.For solving these problems,the biological and NF membrane treating technology of the produced water is studied by experiments.After the produced water is treated by air floatation,biological contact,oxidation and membrane filtration technology,the mass concentration of oil in the treated produced water is less than 0.5mg/L,the suspended solid and SRB cannot be detected,and the mass concentration of calcium ion plus magnesium ion is less than 8 mg/L.The quality of the treated water reaches to the national A1 standard of cycling injection water,and the problem of reservoir scaling is effectively solved.