The LRP® system takes advantage of the motor reversing and servo positioning capabilities of a flux vector variable-speed drive to directly control the sucker rod using a simple rack-and-pinion mechanism. Direct control provides numerous benefits by eliminating the cumbersome, high-inertia mechanics of other systems. Compared to hydraulic reversing systems, the LRP® solution is much more elegant and capable, thanks to electronic control.

The LRP® pumping unit mounts directly to the wellhead. The polished rod runs through a channel inside the rack and is suspended from the top by a conventional rod clamp. The rod is allowed to float inside the rack should the pump or rod stick. An induction motor, coupled to the rack-and-pinion mechanism through a gearbox, cycles the rack up and down to reciprocate the rod. The rack is lubricated with each stroke by submersion into a fully contained oil bath. A high-performance motor and line-regenerative drive can be used to achieve relatively high system efficiency, even on deep wells, without resorting to the massive counterweights used in conventional pumping systems.

The LRP® unit is small, lightweight, and easy to transport. No specialized or heavy equipment is required, which saves on installation costs. It can be carried in a light-duty truck and installed with a 1-ton rig or small picker. Installation is quick and easy and can be handled by two people. Units can be installed and fully operational within a couple of hours.

Since it’s easy to transport and commission, the LRP® system can easily be moved from well to well for temporary installations or to prove reserves.

The low-inertia design of the LRP® system allows it to use a much smaller motor and gearbox than a conventional jack pump. Jack pumps are often oversized to provide the necessary capability. Programmable motion profiles give the LRP® system the effective stroke of a much larger unit. Therefore, a much smaller LRP® unit will provide the same or better production at less cost.

The LRP® system is a smart investment that quickly pays for itself in reduced installation, operation, and maintenance costs. The system can be purchased for a fraction of what a comparable pump jack without any controls would cost. Installation is significantly less expensive because the unit is so easy to transport and set up. Since the unit bolts directly to the wellhead, concrete and gravel pads and other expensive site preparations are no longer needed. Increased production increases revenue and reduced downtime lower operational costs, making the LRP® system a truly economical solution.

The LRP® system is the ideal choice for environmentally sensitive installations. It is quiet, unobtrusive, and does not require site grading, mounting pads, or other well site disruptions. Its low profile and small footprint allow it to blend in where other units would be offensive or prohibited by regulation.

The LRP® system incorporates Unico’s patented SRP sucker rod pump control software to optimize production while protecting the pumping system. Sophisticated variable speed control achieves motion profiles that are impossible through mechanical means. Pump fill is optimally regulated by independently adjusting upstroke and downstroke speeds. Soft landing speed control minimizes fluid impact. An automated valve check determines standing and traveling valve leakage. The control also provides well data reporting, surface, and downhole dynamometer plotting, remote access capability, embedded PLC, automatic fault restarting, and more.

Pump stroke length and spacing can easily be adjusted through software. Upper and lower pump positions are set independently, allowing maximum pump compression by minimizing pump clearance volume when in the full downward position.

Downhole pump speed can be more precisely controlled due to the low inertia of the LRP® mechanism and the constant relationship between motor and rod speed. Pump speed, for example, is quickly reduced prior to fluid impact, attenuating the damaging effects of shock loads on the pump and rod during fluid pound. After fluid impact, speed is quickly increased to maximize production potential..

The LRP® system can operate at speeds as low as 1 spm, as compared to pump jacks without gearbox wipers, which are typically limited to 4 to 5 spm.

Unico’s GMC® Global Monitoring and Control service provides comprehensive Web-based monitoring and reporting capabilities. It is an efficient, cost-effective way to stay connected to daily operations. The service provides real-time monitoring of production and performance data, historical data for analysis, automated well reports, as well as email notification of alarms and other conditions. Operators can view data for all fields, a single field, or an individual well.