Stability Analysis And Sewage Treatment Of Polymer Flooding Produced Liquid

At present,polymer flooding technology is the most mature and economical technology in the three oil recovery technology,and has been widely applied in Daqing oilfield.However,the polymer flooding technology will lead to the increase of the concentration of the polymer in the extracted liquid,which leads to obvious changes in the properties of the extraction liquid,namely,the increase of the viscosity,the high degree of emulsification,the significant increase of the oil content in the sewage after treatment,the increase of the small size oil bead and the increase of the suspended solid content.Water quality is difficult to meet the standard of polymer flooding water quality in Daqing oilfield.The development zone of Daqing Xing Nan development area was fully developed in-2030 2012.The pre slug and reformed slug stage were both injected into 25 million and 7 million salt resistant polymers.In May 2015,7 million in apricot thirteen were stopped by salt resistant polymers.It can be seen that the water quality is getting worse gradually when the injection is gathered.Based on the change of water quality and water injection in apricot thirteen-II joint station,the effects of two kinds of polymer on water quality were studied.The physical parameters of two types of polymer flooding recovery fluid and the stability mechanism of the polymer flooding recovery solution were analyzed.The flocculant is used to screen and compound the single agent,and to compare the effect with the flocculant and the compatibility experiment with other additives.Through the analysis of the technological adaptability of the sewage treatment process in the field,the settlement optimization scheme is put forward.The optimal operation cycle is determined by the actual effect of the field application,and the order of the replacement of the agent is made.Segmental observation,analysis and adjustment,and ultimately determine the relatively economic and reasonable dosing plan.The experimental results show that the stability of the extraction liquid can be enhanced by 25 million high and 7 million medium salt resistant polymers,and 7 million of the salt resistant polymers have certain surface activity,which makes the sewage treatment more difficult and more stable,and the main factors affecting the stability of the extracted liquid are interfacial tension,viscosity and electricity.Polar potential,molecular size and size distribution,interfacial film strength and so on.The interfacial properties and viscosity of the produced fluid have great influence on the stability of the system.At the same time,through the screening of flocculant single agent,it is found that the effect of inorganic flocculant polymerized aluminum sulfate(PAS)and hydrophobic modified cationic flocculant P(DMC-MMA)is the best.On the basis of determining the optimum dosage of PAS,the optimum compound results of 100mg/LPAS+7mg/LP(DMC-MMA)are obtained after the combination of the two,and the compound after the combination is made.Compared with TH-3 experiment,flocculation effect is better than TH-3,and the flocculant is compatible with other auxiliaries of combined station.At last,the combined concentration of 110mg/LPAS+7mg/LP(DMC-MMA)was determined by the observation and adjustment of the field application,and the optimization scheme of the order batch settlement was put forward,and the optimum operation period was 24 h.