Shoulder protection device based on nanofluidic system for packer rubber and the application performance of its elastic layer

To deal with the seal failure caused by stress concentration at the shoulder of packer rubber, this paper proposed a kind of shoulder protection device based on nanofluidic system for packer rubber. This shoulder protection device is composed of wedge-shaped metal ring and ring-like elastic layer. The elastic layer has unique pressure-volume change characteristics and pressure transmission performance, which can eliminate the phenomenon of stress concentration at the shoulder of packer rubber. After filling the elastic layer with the nanofluidic system which is composed of ZSM-5 zeolite and glycerine, this paper carried out pressure-displacement characteristic tests to study the reusability of elastic layer, as well as the pressure threshold of the system under different loading rates and the effective deformation under the maximum pressure. It is indicated that ZSM-5 zeolite-glycerine formula is of great reusability, and it can be used as the filling of ring-like elastic layer of shoulder protection device. When the loading rate varies between 0.01 and 0.1 mm/s, the pressure threshold of the elastic layer can be kept stable in the range of 17±2 MPa. At different loading rates, the effective deformation under the maximum pressure is larger than 58 mm³/g. The higher the loading rate is, the larger the deformation is, which satisfies the performance requirement of elastic layer. By adjusting the formulas of nanometer porous medium and functional fluid, the properties of the ring-like elastic layer are adjustable in a quite large range, so it is applicable to various complex working conditions.