Packer Rubber Tube Performance Finite Element Analysis And Structural Improvements

With the development of the petroleum industry in high temperature, high pressure and complicated deep well, oil production behaviour conditions get increasingly complicated, and the packers, the key tools for production operations, have higher requirements and it will develop towards higher performance, multiple application, multi-behavior, long-endurance, simplified design, large drift diameter and better retractiged elasticity for packers are demanded. These new demands urge researches and development work of packer tend to specialization and products increasingly abundance. At the present time the research on packer, both at home and abroad, mostly focuses on packer system stress analyses, new product development, structure modification, down-hole performance analyses of rubber packer cellular, seal & packer test room study, etc. This paper provided a finite element analysis of sealing properties of the core-piece—packer rubber of packer.This paper adopted non-linearity Finite Element method to simulate the contact press between packer rubber and casing, analyzed infections to sealing of configuration of packer and mechanics parameters of rubber and load-fashion. It also introduced a new method—hyperelastic material curve fitting to acquiring rubber material property constant. Based on the contact relation between rubber of diameter 114mm and casing of diameter 139.7mm, this study established finite element analysis model of single rubber, double rubbers and triple rubbers assemblies. This paper calculated the effects of end face bevel, side bevel and seal length of the single rubber on sealing property, as well as the effects of "anti-extrusion " structure, load mode, friction factor and rigidity to rubber assemblies on sealing property.Research results showed that the contact force between rubber and casing is maximal when end face bevel ranges from 40 to 50 degrees, and it is better when side bevel is 1 degree and it is the best when rubber length is 80mm. The use of "anti-extrusion" structure could increase compressing distance, as a result, it could enhance the contact stress between rubber and casing. The contact stress between rubber assemblies and casing and axial load increase with the increase of compress distance, and it also increases with the increase of material rigidity at the same compressing distance. Friction factor and load mode's influences are prodigious on contact stress, the contact stress at the load end increases with the increase of friction factor in the same compress distance. So the direction of load application on rubber assemblies is determined according to the direction of differential pressure which the packer would bear.This paper analyze the mechanical property of original Y221-114 packer and made structure modification (Using 45 degrees instead of 60 degrees and increasing outside dimension of washer from original 102mm to 113.5mm) .The results showed that these modifications increased the contact stress between rubber and casing. Meanwhile, the study presented a sort of washer structure with trilateral cross section, and this structure could...