Study On Water Shutoff And Technology Of Horizontal Well In Low-permeability Oil Reservoir In Changqing Oilfield

As an important means of effective development of low permeability and ultra-low permeability reservoirs,horizontal wells have been gradually expanded in the application scale of Changqing oilfield,and by the end of 2018,2456 of horizontal wells have been put into operation,accounting for 4.9%of the total number of wells,with an annual output of oil190x10~4t,accounting for 8%of the total oil volume.However,some horizontal wells put into production high water content or short-term water content rise,the loss of capacity is large.It is of great significance to carry out the research on the characteristics of horizontal well water see and the treatment technology of wells,in order to further improve the development effect.Determine the location of the water injection point or the direction of water to provide a basis for the development of management.In this paper,the technology of water plugging and chemical water plugging in changqing oilfield is studied,and the cross-linked particle plugging agent system is optimized according to the characteristics of low permeability reservoir,the temperature resistance,salt resistance and shear resistance of plugging agent system are evaluated,and finally the plugging rate and selective injection of plugging agent system are tested by core plugging experiment.The injection mode and slug combination of cross-linked granular plugging agent system were optimized,the injection mode of the first injection of particle plugging agent,the injection of crosslinking gel plugging agent was determined,and the combination of 0.5PV particle plugging agent+0.5PV gel plugging agent was selected.The field application pilot test of double Shuangping-14 well was selected to evaluate the application effect of plugging agent.