LONG-STROKE PUMPING UNIT

摘要

A long-stroke pumping unit includes a tower; a counterweight assembly movable along the tower; a crown mounted atop the tower; a sprocket supported by the crown and rotatable relative thereto; and a belt. The unit further includes a motor having a stator mounted to the crown and a rotor torsionally connected to the sprocket; and a sensor for detecting position of the counterweight assembly. The pumping unit may include a dynamic control system for controlling a speed of a motor.

主权项

1. A pumping unit, comprising:
a prime mover for reciprocating a rod string; and a dynamic control system for controlling a speed of the prime mover and comprising:
a load cell for measuring force exerted on the rod string;a sensor for detecting position of the rod string;an accelerometer for measuring vibration of the rod string or of a production string;a meter for measuring power consumed by the prime mover; anda controller operable to:
determine position of and load on a downhole pump connected to the rod string and the production string;determine acceptability of two or more parameters of the pumping unit;select a prime objective based on a hierarchy of the parameters and the acceptability of the parameters; anddetermine an upstroke speed, a downstroke speed, and turnaround accelerations and decelerations for the prime objective.