Design And Research On Structure Of The Compressed Sealing Rubber Of The Packer

The technology of the staged fracturing of horizontal well is widely used in stimulation of the thin and low permeability reservoir. As the core element of the fracturing string, sealing behavior of the packer is directly impact on the efficiency of the oil exploration. So, this paper did an in-depth research on the sealing mechanism of the compressive packer to improve its sealing behavior.Sealing mechanism is the core element of packer. In this paper, we firstly put forward the design basis of external bevel angle, external diameter and the height of the packer rubber, designed two kind of movable anti-convex devices which can avoid the rubber-end extruded, and by comparing the performance parameters of common rubber seals, chose HNBR for the rubber material.Secondly, by analyzing the mechanical behavior of the packer rubber, we deduced the equation of the contact stress without anti-convex device under a specify working pressures, and also the equation of the sitting force by dividing the deformation of the rubber into three stages. According to the analysis results, concluded that the packer rubber with big support ring has higher contact stress.The packer rubber is made up by plastic, which with the changes of load is non-linear, so that it must establish the reasonable rubber material constitutive model. Finally, with the ANSYS finite element analysis software, after choosing the Yeoh model, modeling, defining material performance parameters and boundary conditions, we discussed the effect of the rubber shape, the sitting force and the anti-convex device on compressed distance and contract stress. The results of the study show that: the compressed distance and contract stress of packer rubber are also increases while the sitting force increases; with the anti-convex device in the same sitting force, the compressed distance getting further large, the contact stress getting increase, while the rubber-end extruded getting even smaller. Obviously, the anti-convex device can effectively improve the sealing behavior.