Contact Mechanics Study On Annular Sealer

The rubber tube of the packer is an important sealing element in the separating geosphere layers of fracturing operation, while the seal ring is the sealing element to ensure the sealing quality of fracturing string channel. the two annular sealing elements of packer rubber tube and seal ring are taken as research objects, and various methods such as experimental study and numerical simulation are used to study the contact pressure on annular sealing elements, which has important academic value and great prospects for engineering application.First of all, the electrical measuring method is used to qualitatively test and analyze the contact pressure distribution state of rubber tube. Considering the working state of packer rubber tube, the power source of rubber’s compression test come from compression tester, the electrical measuring method is used to test the circumferential strain of casing wall to obtain the rule of contact pressure axial distribution along the rubber tube axis. the elasticity modulus has a small impact on the rubber tube setting. the soft rubber tube will cause slight decline in the contact pressure. The friction coefficient has significant impact on the contact pressure between the rubber tube and casing: the higher the friction coefficient is, the higher the contact pressure between the pressuring rubber tube and casing. The contact pressure between the middle rubber tube and pressure-bearing rubber tube is small, and the decline of friction coefficient can help transmit the axial pressure and rubber tube setting.Secondly, the radial contact pressure transmission and test device developed. Based on the characteristic that fluid cannot be compressed or transmit pressure, the contact pressure transmission and test device was used to transfer the radial contact pressure on continuous curve surface into fluid pressure, measure and calculate the contact pressure between the rubber tube and casing inner wall based on the pressure data from multipoint PT collection system, and fit the contact pressure calculation formula at different locations of rubber tube, in this way to provide solid basis to calculate the contact pressure on rubber tube setting.Finally, five common rubber constitutive models in ANSYS software are used to calculate the contact pressure on rubber tube setting respectively, and by comining the experiment data, we determine the optimal model is the Mooney-Rivlin model. the contact behavior of packer rubber tube setting under different friction coefficients is calculated, and the contact behavior of seal ring sealing under different friction coefficients and compression ratios; the corresponding contact pressure formulas is fit, which can provide reasonable basis for engineering application.