三元复合驱采出水除盐配聚中试研究

Pilot Study on Desalination and Polymerization of Produced Water fromTernary Compound Flooding

以三元复合驱采出水的砂滤出水为处理对象,采用电化学氧化-超滤-电渗析组合工艺对其进行深度处理。组合工艺的最佳条件:电化学氧化电流为40 A,pH为6.5,锌盐混凝剂投加量为800 mg/L;陶瓷超滤膜跨膜压差为0.20 MPa,膜面流速为4 m/s,浓缩倍数为5倍,进水温度为40℃;电渗析运行电压为150 V,回收率为65%。在上述最佳条件下,组合工艺对悬浮物的去除率为97.1%,对含油量的去除率为83.8%,对聚合物的去除率为99.3%,对TDS的去除率为95.2%,出水水质可达到《大庆油田油藏水驱注水水质指标及分析方法》(Q/SY DQ0605—2006)中“5.5.2”矿化度≤400 mg/L配聚用水要求。处理出水配聚性能试验结果表明,三元低矿化度水配聚效果更优。

The combined process consisting of electrochemical oxidation,ultrafiltration and electrodialysis was employed for advanced treatment of the effluent from a sand filter.The optimal conditions for the combined process were as follows:the electrochemical oxidation current was set at 40 A,with pH of 6.5 and zinc salt coagulant dosage of 800 mg/L,and the transmembrane pressure difference for ceramic membrane ultrafiltration was maintained at 0.20 MPa,with membrane surface flow rate of 4 m/s,concentration ratio of 5 times,influent temperature of 40℃,electrodialysis operating voltage at 150 V,and recovery rate of 65%.The removal rates of the combined process under the optimal conditions were as follows:97.1%for suspended solids,83.8%for oil content,99.3%for polymer,and 95.2%for TDS.The effluent complied with the water quality for dissolving coagulant(salinity less than or equal to 400 mg/L)specified in section 5.5.2 in Indexes and Analytical Method of Injected Water Quality in Reservoir Water Flooding in Daqing Oil Field.The results of the polymerization performance test indicated that the polymerization of ternary low salinity water was superior.