Dynamic Analysis of the Sucker-rod Pumping System of Deviated Well Based on LuGre Friction Model

Based on the LuGre friction model, the nonlinear dynamic characteristic of a sucker-rod pumping system of deviated well is simulated. Firstly, the LuGre friction model is introduced, and the values of its six model parameters, which satisfy the engineering's needs, are obtained according to handbook and computation. Then, the vibration of the rod of sucker-rod pumping system is regarded as an axial vibration of multi-segment flexible rod. The loads analysis of rod element is accomplished by means of the finite element method, and recurrence formulas of load and elastic deformation are derived through the finite difference method. The boundary and initial conditions of the load and deformation are evaluated. In the end, a numerical example is given, where a comparison between the elastic deformation of pumping piston obtained based on LuGre friction model and that obtained based on classical Coulomb friction model is made to show that the LuGre friction model describe the friction of sucker-rod pumping system better.