Paper: Hydraulically Actuated Surface Pumping Units

Hydraulic pumping systems have been around for a while now, but in the past they have underperformed against mechanical beam pumps. With improvements in drive and control technology, hydraulic pumping systems are now able to outperform beam units. They have achieve higher speeds without putting added stress on the rod string by optimizing the velocity profile of the actuator. Because the prime mover and actuator are mechanical linked on a beam pump, the velocity profile of the actuator is a sinusoidal; however, the prime mover and actuator on a hydraulic system are not physically connected, so the profile is able to be optimized. Additionally, their speeds and strokes can be easily adjusted with he push of a button, their footprint is much smaller, and there are no safety concerns because there are no external moving parts.