摘要 |
<p>A system comprises a progressive cavity pump including a helical rotor disposed within a mating stator. In addition, the system comprises a rod string having a longitudinal axis, a first end, and a second end coupled to the rotor. Further, the system comprises a rotation retarding device coupled to the first end of the rod string, wherein the rotation retarding device retards the rotation of the rod string relative to the stator. Still further, the system comprises a lifting device coupled to the rotation retarding device, wherein the lifting device is operable to apply an axial lifting force to the rotor.</p> |