Drill Bearing Metal Seal Research

The study shows that the bearing life of the roller bit is one of the key factors affecting the service life of the roller bit.The current metal seal of roller bit is mainly a single metal seal and bimetallic seal,their common point is that the seal structure contains rubber material?In the downhole with high temperature,The seal structure will fail prematurely due to the aging of the rubber.With the increasing of deep wells,ultra-deep wells and geothermal drilling,the temperature of the downhole is getting higher and higher,and the new requirements for the high temperature resistance of the metal sealing structure are put forward.This paper focuses on the research and analysis of the metal seal structure of the bearing of the roller bit under high temperature,and made a new idea of all-metal seal.The mechanical properties of the new type of all-metal bearing seal structure were studied by means of finite element analysis.This paper main research work as follows:(1)Under the condition of high temperature drilling,the failure analysis of bearing seal of roller bit and compound drill bit is carried out to find out the main factors that affect the sealing life.(2)A finite element analysis model of single metal seal structure for roller bit bearing is established.(3)The finite element simulation method is used to analyze the stress in the assembly process,strain and contact pressure of the single metal seal structure of the existing roller bit bearing,and the basic mechanical properties are clarified.(4)The structure of high temperature resistant metal seal was studied,and a new technology scheme was put forward.(5)A finite element analysis model of all-metal seal structure of roller bearing is established.(6)Through the finite element simulation method,the stress,strain and contact pressure of the new all-metal seal structure in the assembly process are analyzed.(7)The influence of different structural parameters on the performance of all-metal sealing structures was analyzed,and the parameters were optimized and improved.(8)The feasibility and performance advantages of the all-metal sealing structure are demonstrated by comparing the mechanical properties of the single-metal seal structure and the all-metal sealing structure after assembly.(9)The axial followability of the all-metal seal structure is better than that of the single metal seal structure by comparing the mechanical properties of the single metal seal structure and the all-metal seal structure in the axial followability.Through the research of this paper,it is proved that the new all-metal seal structure of the bearing of the roller bit has good sealing performance.Compared with the existing single metal seal structure,the all-metal sealing structure greatly improve high temperature performance,because the entire seal is only composed by the metal material.This is conducive to improving the service life of the roller bit in the high temperature downhole,It has a great practical value.