超滤膜处理油田采出水及污染膜的微观分析

Oil Filed Produced Water Treatment with Ultrafiltration Membrane and Micro-analysis of Fouled Membrane

采用纳米Al2O3改性聚偏氟乙烯超滤膜处理油田采出水,分析了污染膜的结构和污染膜上的主要污染物。实验结果表明,超滤膜具有很好的通透性,稳定运行时膜通量达150L/(m2.h)。超滤出水中COD去除率大于90%,其他各项指标去除率均大于98%,超滤出水达到了低渗透油田回注水水质标准(SY/T5329—94《碎屑岩油藏注水水质推荐指标及分析方法》)。污染膜因污染物的存在而使其孔径和孔深度都比新膜减小。污染膜上的主要污染物为含有一定长碳链的烃类衍生物,主要是油田采出水中的油类物质。污染膜上的主要无机元素为Ca、Mg和Al,还有少量的Si、S及Fe。

The ultrafiltration membrane prepared was used to treat oilfield produced water. The with nano-Al2O3 modified polyvinylidene fluoride structure of the fouled membrane and the main contaminants on it were analyzed. The experimental results show that the permeability of the ultrafiltration membrane is good and the membrane flux can reach 150 L/（ m^2·h） in stable running state. The quality of the permeation water can meet the standards for lower infiltrating oilfield injection water with over 90% of COD removal rate and over 98% of removal rate of other indexes. The aperture and deepness of the fouled membrane are less than those of the new membrane due to contaminant existing. The main contaminants on the fouled membrane are hydrocarbon derivatives, which have carbon chains with certain length, mainly composed of oily substances in oilfield produced water. The inorganic elements on the fouled membrane are Ca, Mg, Al mostly and Si, S, Fe measly.