Design Of Drillable Packer And Study Of Concentric Double Pipe Injection Separation System

As oil fields are continuously exploited,reservoir energy decreases and oil well production decreases.It is necessary to increase oil recovery by injecting water into reservoir to replenish reservoir energy.The separate injection technology is difficult to meet the requirements of seal inspection and fine water distribution for each layer in oilfield development.The structure design of oilfield waterflood string is not standard,and the supporting tools lack of standard and basis.Affected by oilfield depth,pressure,temperature,etc.,the validity period of the pipe string and supporting tools is short.The poor sealing and unsealing of the packer in the injection separation process increase the probability of overhaul,and it is difficult to meet the requirements of multilayer reservoir injection separation.In view of the above problems,research on supporting technology of drillable packer type concentric double-pipe injection separation process system was carried out to realize the upgrading of reservoir injection separation technology,and solve the problems of difficult packer unsealing and short service life of supporting tools.In this paper,a concentric double tube dispensing technology is proposed.A concentric double-pipe injection string combination is designed.The buckling and axial deformation of concentric double-tube string are analyzed,and the strength of concentric double-tube string is checked.A drillable packer with concentric double-pipe splitter technology was designed and manufactured.ANSYS software is used to simulate the stress distribution and deformation of the drillable packer’s rubber drum,center pipe and upper jacket in practice.The drillable packer was tested in the laboratory,and the results showed that the drillable packer was set smoothly,unsealed reliably,had good overall sealing performance,and had good drilling and milling performance.The drillable packer-type concentric double-pipe injection separation process has been applied in the No.1 Oil Production Plant of Changqing Oilfield,which improves the level of stratified waterflooding technology,improves the qualified rate of stratified waterflooding interval and the waterflooding development effect,enhances the completion ability of oilfield enterprises,and the overall application effect is obvious.It has guiding significance to the stable production of oilfield.