Study On Plugging Removal And Injection Enhancement In Polymer Flooding Wells In Daqing Oilfield

The experiment and application of polymer flooding technology have been carried out successively in Daqing oilfield.With the continuous injection of polymer in wells,the expected oil displacement effect has been achieved and the production of oil wells has been improved.However,the injection well has been blocked due to the change of injection properties and reservoir conditions,leading to an increase in injection pressure and a decrease in the imbibition index of the formation affecting the performance of polymer flooding.Plugging problems of polymer injection wells are highlighted,which must be resolved to guarantee the effect of polymer flooding.In order to remove the plugging problem of polymer injection well,effective plugging removing agent must be studied.In this paper,the production situation of polymer injection well in Daqing oilfield is discussed.We analyzed components of blockage material,and studied the cause of the blockage,then put forward the necessary technical measures to effectively solve the plugging problem.Through a variety of laboratory chemical tests,we studied the efficient plugging removing agent system.And confirmed by the scene,the best plugging removal effect was achieved.And after the plugging removal system was implemented,the reservoir protection agent was applied to solve the pollution problem of oil reservoir.It can prolong the service life of polymer injection well.Through the plugging removal analysis and the production practice of polymer injection well in Daqing oilfield,it was proved that good plugging removal effect has been achieved.