Simulation Analysis And Optimization Of Structural Performance Of Hydraulic Pressurizer

In the process of drilling operation in extended reach well and horizontal well,the WOB of drill bit caused by drill collar is close to zero,and the bit is stimulated by the axial vibration,causing vibration of the upper drill string.Hydraulic thruster is mainly used at home and abroad to solve the problems of drill bit support pressure and drill string vibration.The hydraulic thruster flexibly connects the drill string with the lower drill tool,and provides energy for the drill bit through the throttling pressure drop of the drill bit,thus reducing the coupling vibration of the drill string and the fluctuation of WOB and,effectively solving the problems of drilling jumping and uneven drilling delivery.The existing hydraulic thrusterr has a short working stroke,which is difficult to control in the working section.It can only reduce the axial vibration,but can not reduce the torsional vibration.The sealing structure of the hydraulic thruster is easy to cause erosion and wear under the high-speed erosion of drilling fluid,resulting in the leakage of drilling fluid in the piston chamber and even,a dropof WOB to zero.In order to solve the above problems,a new type of hydraulic thruster is designed in this paper,and the finite element analysis is carried out.The work done in this paper is as follows:(1)Analyses conducted in this study included the development,the working mechanism and various failure modes of hydraulic thruster.In addition,the main working mechanical characteristics of hydraulic thruster components were clarified.(2)A hydraulic thruster has been designed to,calculate the size and strength parameters of the hydraulic thruster's torque transfer mechanism and torque vibration reduction mechanism.A ssembly drawings and parts drawings were drawn and,the three-dimensional solid modeling and virtual assembly of the hydraulic thruster were completed.(3)The finite element simulation model of the cylinder liner,mandrel and torque vibration reduction mechanism of hydraulic thruster was established.The finite element analysis of the components of hydraulic thruster was carried out by using ABAQUS finite element software,including the static analysis of the cylinder liner,mandrel and torque vibration reduction mechanism and the modal analysis of the mandrel.(4)A sliding ring combined seal structure was designed.Finite element simulation of the seal structure was carried out through the loading method of fluid pressure and osmotic load.Consequently,the influence rule of structural parameters of single factor sliding ring on the sealing performance was obtained.Orthogonal test was applied to analyze the influence of structural parameters of multi-factor sliding ring on the sealing performance of piston.On this basis,the size of sliding ring was optimized.(5)Based on the spring-damp model and Karnopp friction model,the mathematical model of axial and torsional vibration of the drill string with hydraulic thruster was established,and Simulink was applied to analyze the dynamics of drill string with hydraulic thruster.Therefore,the vibration reduction performance of the hydraulic thruster was evaluated.By upgrading the hydraulic thruster and studying its sealing structure,the torsional vibration reduction and sealing performance of the hydraulic thruster were improved,which provides a reference for improving the vibration reduction effect and prolonging the service life of the hydraulic thruster.