A StringSense Integrated Drill String Measurement System attached to a rig onsite

StringSense Integrated Drill String Measurement System

Accurate, reliable surface measurements directly from the drill string.

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NOV’s StringSense™ integrated drill string measurement system provides a means of surface measurement directly on the drill string, enabling integrated downhole and surface data to enhance the drilling process. As a patented instrumented internal blowout preventer (IIBOP), the StringSense system delivers more accurate and dependable surface drilling data and allows you to extend the operating envelope when drilling near the technical limits of the well.

The StringSense system provides measurements for direct drill string tension and compression, drill string torque, revolutions per minute, bending moment, and internal pressure immediately below the top drive's main shaft, transmitting the data wirelessly to a surface receiver system. Using accurate drill string tension and torque data via direct measurements, you can reduce the risk of parting strings, extend drilling envelopes through improved torque and drag models, and improve your drilling equipment efficiency.

The StringSense system uses the latest strain gauge technology and has the advantage of being physically located in the direct load path of the drill string, which eliminates many components of measurement error due to friction in the hoisting system and other forms of mechanical interference in conventional drilling measurement devices. The system's valve geometry is identical to original IBOP features, and OEM components are used to ensure the same high-quality seal as a standard NOV valve assembly. Battery life ranges from 4 to 6 weeks, depending on signal transmission frequency settings, and batteries can be safely replaced one at a time over the well center to maintain a continuous data stream. Three proprietary patch antennas provide 360° coverage from the drill floor to the top of the derrick.

We’ve designed the StringSense system as a direct replacement for the existing upper IBOP on the TDS-10, TDS-11, and TDS-4 top drives, eliminating the need to modify the pipehandler or elevator links.


  • Accurate mechanical work measurement for top drive
    • Provides the necessary data for improved torque and drag modeling
    • Facilitates decreased nonproductive time
  • Same form factor and operation as existing upper IBOP for drop-in replacement
    • Requires no change from original installation procedures
  • Direct measurement of multiple variables at the drill string
    • Eliminates external elements that would affect accuracy of measurements
  • Driller can adjust quickly to correct many issues
    • Reduces wear on the top drive and drill string
  • Offered in an IntelliServ™ modified model
    • Provides instantaneous measurements through high-speed telemetry
  • M/D Totco StringSense NOV's Drillstring Measurement System Case Study
  • M/D Totco StringSense NOV's Integrated Drillstring Measurement System Case Study
  • StringSense Integrated Drillstring Measurement System Flyer
  • StringSense Integrated Drillstring Measurement System TDS-4 Spec Sheet
  • StringSense Integrated Drillstring Measurement System TDS-11 Spec Sheet
A closeup to a StringSense Integrated Drill String Measurement System attached to a rig

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