HIGH-SPEED ROD-DRIVEN DOWNHOLE PUMP

摘要

Abstract A surface drivehead drives a downhole pump by rotating a rod string at the surface. The downhole pump can be connected downhole to the rod string via a downhole latching mechanism. The surface drivehead has an assembly that can move the rod string upwards or downwards along an axis to either increase or decrease rod string tension. During rod string rotation, rod tension is monitored. If rod string tension changes during rotation, the surface drivehead can automatically compensate by moving the rod string upwards or downwards along the axis to either recapture or eliminate tension. In this way, the surface drivehead can maintain a substantially constant rod string tension to drive the downhole pump at high speeds. -13 -14 --- 12 4-- FIG. 2A