高矿化度稠油采出水外排生物处理技术应用研究

Application of biological treatment technology for the outflow of produced water from heavy mineralized heavy oil

为探索微生物水处理技术用于高矿化度稠油采出水外排处理的可行性,针对新疆油田某联合站稠油污水可生化性差的特点,开展了采出水外排微生物处理技术研究。在掌握稠油热采污水水质以及COD构成分析的前提下,相继开展了混凝/气浮、高级氧化等多种预处理技术的室内研究工作,进一步提高了外排采出水的可生化性。同时,采用驯化培养出具有良好降解性能且盐度适应范围广的高效优势菌种,最终确定了“混凝预处理+生化处理”的总体处理工艺思路。室内模拟实验和现场试验结果表明,联合站稠油热采污水通过“混凝沉淀+水解酸化+接触氧化”的工艺处理后,外排水中COD、BOD 5、石油类和挥发酚的平均去除率分别为85.19%、96.00%、81.82%和95.01%,可以有效地实现联合站稠油采出水达标外排至人工湿地。

In order to explore the feasibility of microbial water treatment technology in the treatment of high-salinity heavy oil produced water effluent treatment,in view of the poor biodegradability of heavy oil wastewater in a combined station in Xinjiang oilfield,a study was conducted on the produced water effluent treatment.Under the premise of grasping the water quality of heavy oil thermal recovery wastewater and analysis of COD composition,research work on various pretreatment technologies such as coagulation/air flotation and advanced oxidation has been successively carried out,which further improved the biodegradability of the discharged water.At the same time,domestication was used to cultivate high-efficiency dominant strains with good degradation performance and a wide range of salinity adaptation,and the overall treatment process idea of"coagulation pretreatment+biochemical treatment"was finally determined.The results of laboratory simulation experiment and field test showed that:after the heavy oil thermal recovery wastewater from the combined station was treated by the process of"coagulation precipitation+hydrolysis acidification+contact oxidation",the average removal rates of COD,BOD 5,petroleum and volatile phenol in the external drainage are 85.19%,96.00%,81.82%and 95.01%,respectively,which indicated that the discharge of the heavy oil produced water from the combined station up to the standard could be effectively achieved.