Wear Failure Mechanism and Main Influencing Factors of All-Metal Progressing Cavity Pump AMPCP

Abstract All metal progressing cavity pump(AMPCP) has excellent high temperature resistance and corrosion resistance and shows good adaptability in heavy oil production. With the development of pump processing techniques and manufacturing, the performance and reliability of AMPCP have been improved rapidly. However, the wear failure issue of the AMPCP s still considerably severe, leading to high total-life-cycle cost and limiting the commercial application of the products. This paper discussed the mechanism of the wear behavior of AMPCP through numerical simulation and experimental analysis. The main influencing factors of AMPCP wear failure are analyzed as well, which plays an essential guiding role in the pump optimization design. This paper presents the numerical simulation of the wear behavior of AMPCP under different clearances, structural parameters, and operating speeds and discusses the influence of these parameters on the friction torque and wear behavior. Studies show a series of valuable results: 1) The clearance value between rotor and stator has the most significant impact on the amount of wear. With the change of the pump clearance, the change in the contact area and the amount of wear between the stator and the rotor performs a nonlinear relationship. 2) Although eccentricity changes the inertia effect caused by the eccentric movement of the rotor to a certain extent, it has little effect on the overall friction and wear. 3) The amount of wear and the rate of wear are linearly related to the speed, i.e. the higher the speed, the faster the wear increases. However, there is little difference in the amount of wear at different speeds for high viscosity lifted fluids. In this paper, the wear analysis model of AMPCP is established for the first time. The evolution of the wear bands between the stator and rotor of the AMPCP is demonstrated by a three-dimensional explicit dynamic model, and the influence of different factors on the wear of AMPCP is discussed in detail. This paper has laid a necessary theoretical foundation for the optimization design of AMPCP. It also applies essential guidance for further improving the operating performance of AMPCP.