Key Technologies And Corresponding Mechanical Device For RDM Top Drive Swivel

Reelwell Drilling Method(RDM)is a two-layer concentric drill pipe for drilling fluid into the outflow channel to solve the drilling problem.This project come from Drilling Technology Research Institute of Shengli Petroleum Engineering Corporation Sinopec " Research On Key Mechanical Equipment For RDM ".The goal was to develop a top drive device swivel that meets the specific process requirements of RDM,referred to as a Top Drive Swivel.This paper focused on the key technology of the Top Drive Swivel mechanical system.First of all,the mechanical model of V-ring was established based on the elastic method and the sealing theory.By using Hooke's law,the axial direction of the V-ring,the circumferential,the radial stress were obtained by deriving the equilibrium equation,the geometric equation,the deformation coordination equation and the physical equation.Then,we derived the Lame equation.The axial displacement equation of the seal ring which is satisfying the sealing pressure was deduced under the contact stress,and then we had obtained the minimum axial deformation amount of each seal.Secondly,for problem of the vibration and creep phenomena of the Compensator piston under the low speed movement,the continuity equation of drilling fluid and lubricating oil and the dynamic balance equation of the piston were established,and then we had plotted the Compensator dynamic block diagram and got the transfer function of the compensator.the natural frequency,the moving speed pulsation frequency and the flow step response were studied.Through the nonlinear analysis of the dynamic equilibrium equation of the compensator,the free vibration equation of the system was deduced.the Van der Pol equation was solved to obtain the boundary condition of the dynamic stability of the dynamic compensator.Thirdly,the mechanical model of the clamp connector was established,and the formula of the cylinder tension was deduced which is universal to the general taper seal problem.We had carried out the non-linear finite element analysis of the O-ring between the base and the hub to study the sealing performance,then the maximum contact stress and the reaction force of the base are ensured,and the calculation formula of the cylinder tension of the clamp connector is improved.The finite element analysis of the clamp connector is carried out to obtain the stress distribution of the dangerous part and the stress distribution of the whole clamp.The dangerous area is improved which provides the theoretical basis and the improvement suggestion for the reasonable design of the clamp connector.Finally,according to the characteristics of RDM and design goals or requirements,we put forward a Top Drive Swivel overall technical scheme,then we designd the parts.Through the analysis of the collision problem caused by the longitudinal vibration in the drilling process,the mechanical system is optimized for the rated load.The dynamic seal of the outer tube and the swivel shell is the hardcore of the Top Drive Swivel,a new type of drilling fluid seal system is designed by using the V-ring.The series dynamic pressure compensation system is proposed for the pressure concentration caused by the seal failure.We made a physical prototype and made an experiment on the oil well..