Study On Sealing Performance Of Rotary Liner Hanger Bearing In Ultra-deep Well Drilling

Rotating liner cementing has become the commonly method,which can improve the cementing quality, protect oil and gas reservoirs and save a lot of cost in the ultra deep well, complicated well. As the key component of the rotating liner hanger, the working environment of bearing is high temperature and high pressure with mud, the working condition is very bad. If the bearing seal failure, mud and other debris into the bearing will accelerate its wear. Sealing performance will directly affect the normal operation of the rotating liner hanger. In this paper, the basic design and performance research of bearing seal of rotating liner hanger were studied.According to design conditions of rotating liner hanger, the structure of bearing seal,the material selection and the installation method were basicly designed in this paper.Lip rubber sealing ring is used in super-elastic material, and it is also highlighted super elastic and nonlinear constitutive theory, in which the non-linear properties, material properties, and state properties of geometric were considered into account. Further the parameters of rubber material were determined. The two-dimensional axisymmetric finite element models were built and the contact type, the boundary conditions,the mode of loading were established.Applying large-scale non-linear finite element software ABAQUS, the effects of different value of initial interference on Von Mises stress and the contact pressure distribution between sealing surfaces were firstly studied under the preload condition.Secondly, the effects of different service pressure on Von Mises stress and contact pressure were considered under the work condition. The result shows that the maximum contact stress increases with the increase of value of initial interference, the maximum contact stress is always bigger than service pressure with the action of different conditions, which satisfies the sealing condition for the lip sealing ring.Then, based on the thermoelasticity and theoretical analysis of thermal stress, the influences of temperature load and initial interference on Von Mises stress and the contact pressure between sealing surfaces were discussed by the analysis method of order coupling thermal stress. The result shows that temperature changes have little effect on the sealing performance.Finally, the failure modality and the factors influencing sealing performance are discussed. The coefficient of friction as the key considerations are analyzed, which can provide a reference to improve the service life of bearing seal.For reducing the experimental cost and shortening the research and development circle, non-linear finite element analysis on bearing lip rubber seal ring is an effective method. The method settles a foundation for bearing seal structure design optimization and performance analysis of the seal performance study.