Mechanical Characteristics Analysis Of Hydraulic Expandable Packer Tubing Strings

Hydraulic expandable packer tube is mainly used in fracture operations,the pressure create ballooning effect under the string causing the tube axial deformation,even cause the packer loss of seal,thus affecting the operation success or failure.this paper study on the hydraulic expanding packer string and packer rubber.In this paper use the theory and method of Hydraulic expandable packer tube in the working process of mechanical behavior analysis,were obtained gravity,buoyancy,fluid resistance,piston,temperature effect and bulging effect caused by a calculation formula of axial deformation of column tube.Derived the force calculation formula of the three stage for hydraulic expandable packer tube ballooning effect.Through the analysis of the deformation stage of the hydraulic expandable packer,the formula of the axial load formula of the working face and the shoulder,the contact stress of the plastic cylinder working surface.The calculating formula of the friction force between the rubber and the casing.Finite element analysis results show:The fracturing fluid flow through the packer when the jet fracture occur,with packer rubber tube temperature decreases rubber stress increases,when the temperature below 90? the rubber stress decreases,when the temperature below70 ? the rubber stress increases too.Under the pressure,from the ends of the rubber to intermediate the packer rubber contact stress increasing.