A dive into the applications of power sections in various downhole environments
Written by Chris Bondy
Executive Summary
Discussion
WOS provides a wide range of motors with varying sizes, speeds, torques, and differential pressures, and stator materials. All have substantial performance records in many basins across the country and the world. Our operations in the northeast primarily rely on our tried-and-tested POWR Motors, which feature an elastomer stator and perform exceptionally well in the Utica and Marcellus. Through 2025, the overall WOS BHA reliability rate for 2025 was 99.15% across 583 drillout operations. Only 24 of which were completed with a Terminator T1000 Motor, and only 22 of 55 in the Haynesville shale.
One of the guiding principles of WOS is that of constant improvement; performance data from every drillout is meticulously reviewed and analyzed, from which we draw conclusions that are fed back to the R&D team for improvements. Each and every tool failure is thoroughly investigated, and the results are presented transparently to the customer, but also fed back to the R&D team.
The latest addition to the WOS fleet of motors is the 3-1/4” Judge Motor with an elastomer stator, rated for 8BPM and boasting a high maximum torque output. In the northeast, the Judge has been used in over 25 drillouts and from the outset has proved itself as a very capable motor equipped to drill out the deepest wells in the Marcellus. With modest differential pressure, the Judge is an excellent choice for high-flow pressure-limited operations.
The WOS line of Terminator T1000 Motors is the line of metal stator (metal-to-metal) offerings from WOS. The T1000 was specifically designed for the harshest downhole conditions and is more than ready to tackle challenging wells. Thus far, it has been proven in Geothermal operations in the Rockies, the high temperature and pressure of the Haynesville Shale, and in sour service conditions in Saudi Arabia (Hydrogen Sulfide). When used in applications where nitrogen or media would like to be pumped to reduce friction or lift heavier fluid the Terminator is chosen over elastomer for its durability in these challenging environments. While the T1000 has the capacity to withstand some of the most extreme well conditions in the world, it may be superfluous to rely on it in basins with more conventional downhole conditions.
For example, in the Bakken Shale—known for its moderate downhole temperatures and pressures—the WOS POWR Motor is the preferred choice and performs excellently. There are a variety of choices for motors and power sections offered by WOS. The Terminator T1000 Metal-to-Metal Motor is designed for applications with strict temperature and chemical limitations. When conditions are not overly extreme, the WOS POWR Motor and its elastomer stator options are engineered to handle high flow and high downhole pressure operations. All WOS operational recommendations are developed through data-driven analysis of extensive performance figures, and these recommendations provide customers with an optimized balance between reliability and performance.
Comparison of Motor Specifications
| WOS Motor Line | Stator Material | Temperature Range | Flow Rate Range | Size Offerings |
|---|---|---|---|---|
| POWR | Elastomer | Up to 350 deg F | Up to 7 BPM (300 gpm) | 1-5/8″ to 3-1/2″ |
| Terminator T1000 | Metal | Up to 1000 deg F | Up to 5 BPM (210 gpm) | 1-5/8″, 2-7/8″, 3-1/8″ |
| Judge | Elastomer | Up to 350 deg F | Up to 8 BPM (330 gpm) | 3-1/4″ |