Logging Wireline Formation Tester PACKER Rubber Surface Finite Element Analysis And Optimization

Petroleum and petrochemicals is great pillars of the national economy,oil exploration and development is most important in oil industry,and oil well logging instrument and its research is the premise to safeguard the oil exploration and development smoothly.In this paper,logging wireline formation tester's key modules—dual-PACKER modules make as following aspects studies:1.Analyze the rubber material which is different from the isotropic linear material properties,based on experimental collected data to make sure their stress-strain relationship, search for rubber material's research methods and the sealing properties,use of rubber material's incompressible and hyperelastic characteristics,use one of rubber material finite element methods-hybrid finite element method,to solve overall displacement vector u, Kirchhoff stress vector t and hydrostatic pressure parameters h of the PACKER rubber surface when they are in contact with the wall.At the same time,according to the hardness of rubber and the finite element method,slove the Mooney-Rivlin model parameters of rubber material.2.According to the working principle of the dual-PACKER modules,analyze and establish the mechanical model,design supporting and sealing experiments,and at last make an analysis to experimental data.Supporting experiment make sure the extent of supporting different sizes wall with different specifications's rubber blocks.The results proved that the rubber block can support the whole instrument when system pressure is 24MPa,sealing experiments obtained the best scope and size when they match different sizes wall with different specifications's rubber blocks,the match is best when the difference between rubber size and well's diameter is the range of -1.625～3.0 mm.3.According to the characteristics of rubber material,using ANSYS software to study the rubber material non-linear,large strain,as well as non-linear contact problem,analyze the contact pressure and rubber stress when casing wall match with six kinds of best specifications,get that semi-rubber O-ring radius and its location is the key factors in sealing.4.Use of ANSYS optimization modules,optimize six kinds of the best specifications of the rubber block,get the best value and best location of the semi-O-ring radius.Through optimization,improving the design of rubber block size,getting the best sealing after optimization.