Adding an electric motor and eliminating a mechanically actuated arm lead to a more reliable system.
by Mike Thomas
April 20, 2016

In the artificial lift market, a new type of rod rotator is available to provide users with an intelligent, versatile and reliable rod string wear solution for all rod pumping units.

During rod pumping operations, the constant up-down motion can cause erosional wear on the sucker rod. Rod 
string rotation used in conjunction with rod guides not only removes paraffin from inside the production tubing, but it 
also distributes wear evenly for the rods and rod couplings. 
This process extends periods between workovers and minimizes downtime.

The new type of rod rotator represents a departure from traditional mechanical rod rotators in the industry. This specific artificial lift technology helps to overcome common industry headaches that operators face with benefits such 
as eliminating difficult setup for easier installation and 
adding rotational monitoring, both on-site and remotely.

Image 1. An intelligent, versatile and reliable rod string wear solution for all rod pumping unitsImage 1. An intelligent, versatile and reliable rod string wear solution for all rod pumping units (Images courtesy of NOV)

Some experts recommend that end users use tubing rotators during artificial lift operations in conjunction with any type 
of rod rotators to increase tubing wear life in the same fashion. Wear prevention systems allow the operator to reduce downhole maintenance costs and production downtime by extending the service life of rods and tubing in a wide range of well conditions.

Industry Challenges

This technology’s development addresses some artificial lift industry challenges that users in the field currently face. Traditionally, rod rotators were designed 
to operate with conventional pump jacks in mind. With 
so many modern unconventional rod pumping systems 
being introduced to the market today, installing 
traditional rod rotators can be a difficult and sometimes impossible assignment.

In certain situations, operators may not know where to install traditional rod rotators on unconventional technology because the equipment is not capable of fitting on the unit. 
This requires having to set up extra equipment, such as 
custom brackets.

Image 2. The elimination of the mechanically actuated arm and cable in the design allows operators to install a much more reliable system.Image 2. The elimination of the mechanically actuated arm and cable in the design allows operators to install a much more reliable system.

Using the new addition of the electric motor on the rod rotator can remove some difficulties associated with setting 
up the traditional mechanical arm and cable system. Because 
of the removal of the two pieces of equipment from the traditional rotator in the new type of rod rotator, operators 
may more easily and safely install a system on unconventional units.

A second major concern behind developing this technology was that operators were not always aware of an issue occurring during rod rotation. Users had no visuals or feedback and would have to physically check the unit in remote environments to see the rod rotator’s condition. If the rod rotator is left unchecked, rod erosion can be costly to repair.

This new type of rod rotator offers an added integral rotation sensor that monitors optimal performance and immediate failures during operation. The integrated rotation sensor, coupled with the control box, monitors performance and generates an alert if a failure occurs.

This technology can increase sucker rod life, increase well production and decrease downtime during operations. It can be used on various hydraulic rod pumping systems, as well as many unconventional systems.

Other Potential Benefits

The new rod rotator includes ground-level and remote-rotation monitoring results that can be sent directly to a user’s portable device. The technology can also be configured during cold and harsh environments.

The low-voltage Class 1/Division 1 rated motor is used with a high gear ratio to rotate the rod string. Because of the elimination of the cable used to actuate the gear that rotates the rod string, there is greater control over rotation per day and a reduction of rod stress related to torsion.

Operators can receive notification through their added supervisory control and data acquisition (SCADA) system software to inform them that the rotator has stopped turning.

Remote monitoring is an important feature for the artificial lift industry today and in the future. Access to troubleshooting issues and feedback 
via a user’s supervisory software is crucial to keep production up in a changing market.

Ideally, all equipment will have monitoring, and maintenance personnel will be dispatched when they receive an alarm if there is an issue with the operating technology. By using remote monitoring, operators will cut down on labor and costs, especially in isolated locations and extreme environments.