Study On The Application Of Electrolysis Brine Sterilization Technology

Oil field adopts waterflood development to extract crude oil,which produces a huge amount of oily sewage.The treatment and reinjection of oily wastewater is the most important way of oilfield water,which can not only meet the needs of oilfield development,but also reduce pollution and save resources.There are bacteria in oilfield sewage,such as sulphate reducing bacteria,iron bacteria,saprophytic bacteria and so on.If the bacteria treatment is not up to the standard,it will produce serious corrosion,block the pipeline,damage the oil layer,and cause the decline of the formation water injection capacity.Therefore,it is necessary to effectively control the growth of bacteria.After a long time of production practice,electrolytic salt water sterilization technology is widely used in Xinjiang oil fields.In essence,the sterilization technology of electrolytic salt water relies on effective chlorine generated after electrolytic salt water as fungicide to kill the bacteria in oil field.Due to various reasons,there are some problems in the production and operation of electrolytic salt water plant in Xinjiang oil field.In this paper,the sterilization technology of electrolytic salt water has been further studied,the stability,sterilization ability and long-term effect of residual chlorine in backwater injection have been comprehensively studied,and a series of application evaluation of the sterilization device of electrolytic salt water has been carried out in the field experiment.The results show that electrolytic salt water has strong bactericidal effect on three kinds of bacteria in oil field,and can produce strong bactericidal effect under relatively small dosage and wide water quality environment,and can meet the target of bacteria in oil field water injection.The decay process of residual chlorine is a continuous process.With the extension of time,the residual chlorine is consumed and the system loses its inhibition ability to bacteria.The long-term effect of electrolytic salt water on the inhibition ability of the three kinds of bacteria can be realized by appropriately increasing the amount of electrolytic salt water.S^2-in backwater injection will cause great consumption of electrolytic salt water and seriously affect the sterilization effect.The field test shows that the electrolytic sterilizer can ensure the water quality at the end of water injection wellhead reaches the standard in the clean water treatment system.However,in the dilute oil wastewater treatment system,under the condition of relatively stable water quality,the electrolytic sterilization device can ensure that the bacteria content of the outbound water and the middle part of the line water injection station reaches the standard,but when the pipeline along the way is long,it cannot ensure that the bacteria content of the end station and the injection well reaches the standard.When the inflow condition is poor and the content of reducing substances such as sulfur ion is high,the performance of sterilization device of electrolytic salt water will be seriously affected.It is necessary to properly treat sulfur ion and other reducing substances in the front end so as to realize the stable operation of electrolytic salt water sterilization device and ensure the stable operation of oil field water flooding operation.Electrolytic salt water sterilization technology is green,environmental protection and economical,which has the basis of widespread application in Xinjiang oil field.