| Polymer flooding is a kind of exploitation method that can effectively exploit the remaining oil and greatly enhance the recovery,and has been widely used in oilfield development.Since the 1960 s,polymer flooding has been applied to oilfield development.After years of development and exploration,polymer flooding technology has become increasingly mature.But for more complex environments,conventional polymers often cannot play a better role.In order to solve this problem,this paper studies the properties of a new type of salt-resistant polymer,and analyzes the influence of the salt-resistant polymer flooding produced sewage on the characteristics of the salt-resistant polymer,which provides a theoretical basis for the application of salt resistant polymer in field.First of all,by preparing common polymer and salt-resistant polymer solution,this paper conducts a comparative study on the viscosity increase,temperature resistance,salt resistance and acid and alkali resistance of the two polymers.The solution was placed in an environment of 70°C for 90 d aging.The microstructure of salt-resistant polymer solution was observed,which provided a basis for the feasibility of preparing salt-resistant polymer by using salt-resistant polymer flooding produced sewage.Secondly,salt-resistant polymers were prepared by using salt-resistant polymer flooding produced sewage and mineralized water respectively.The characteristics of the two kinds of salt-resistant polymer systems were compared and the influence of salt-resistant polymer flooding produced sewage on salt-resistant polymer properties was studied.The feasibility of preparation of salt-resistant polymer by salt-resistant polymer flooding produced sewage was studied.Finally,the oil displacement experiment was carried out by using the salt-resistant polymer solution prepared with different water quality.The results show that,compared with ordinary polymers,saltresistant polymers have better viscosity,temperature resistance,salt resistance and acid and alkali resistance.After 90 days of aging at 70?,the salt-resistant polymer solution retains a high viscosity.The salt-resistant polymer flooding produced sewage will not have a great impact on the properties of the salt-resistant polymer.There is little difference in viscosity,rheology and viscoelasticity between salt-resistant polymer solution prepared by salt-resistant polymer flooding produced sewage and mineralized water.Bacteria have great influence on the viscosity of salt-resistant polymer solution.Therefore,when using the salt-resistant polymer flooding sewage to prepare the saltresistant polymer,the bactericide should be used.The oil displacement experiment shows that the better the water quality of salt-resistant polymer flooding produced sewage,the better the oil displacement performance of salt-resistant polymer prepared.There is little difference in recovery between the salt-resistant polymer prepared with mineralized water and the salt-resistant polymer produced sewage.There is little difference in recovery between the salt-resistant polymer prepared with mineralized water and the salt resistant polymer produced sewage.The recovery is little difference when using salt-resistant polymer by mineralized water and salt-resistant polymer produced sewage.The salt-resistant polymer solution is mixed with mineralized water and salt-resistant polymer flooding produced sewage,and the final recovery is not much different from the salt-resistant polymer prepared by using salt-resistant polymer flooding produced sewage.So in the field application,the method of mixing the produced sewage and mineralized water by salt-resistant polymer flooding can be used to realize the maximum utilization of resources. |
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