Research On Sealing Performance And Wear Mechanism Of Dynamic Seals

As the depth of drilling downhole increases,the temperature and pressure of drilling conditions continue to increase.Under the conditions of deep wells,the high temperature and high pressure resistance of the existing downhole tools can no longer meet the requirements for use under this working condition.In this paper,a dynamic sealing ring suitable for high temperature and high pressure drilling conditions is studied,which has certain guiding significance for the selection of high temperature seal materials and structural parameters.The article first introduced the current status of dynamic seal structures,materials,and experimental research at home and abroad,and used a large-scale finite element analysis software ANSYS to create a dynamic seal based on the material parameters and dimensions of the seal ring under consideration of the triple nonlinearity and high temperature conditions of the seal material.Three-dimensional assembly model for rings,seal grooves,and shafts.Secondly,the paper simulates and analyzes the dynamic seals in drilling tools under high-temperature conditions in the well.Through the analysis of the contact stress and Von Mises stress of the dynamic seals,it is concluded that the maximum contact stress of the seals increases with increasing temperature.Von Mises stress is inversely proportional to temperature.The finite element simulation analysis of the sealing structure parameters(groove depth,length of lower contact edge,compression ratio)affecting the sealing performance of the dynamic seals shows that the maximum contact stress,Von Mises stress and compression ratio of the seal ring have a linear function relationship;As the length of the lower contact edge increases,it shows a decreasing trend.Finally,the effects of the fluorine content of the seal ring,the height of the seal ring,the width of the seal contact surface,and the compression ratio on the friction and wear properties of the seal ring were investigated at room temperature using dry friction and wear tests,and the wear mechanism was analyzed.It is concluded thatwith the increase of the fluorine content,the wear volume and the average temperature rise of the seal ring gradually decrease;with the increase of the compression ratio,the wear amount and the compressibility have a linear relationship;with the increase of the width of the lower contact edge,the seal ring Both the amount of wear and the temperature increase decrease accordingly.