Electromagnetic Measurement While Drilling (EM MWD)


At Native Navigation, we're not easily satisfied with MWD systems and average performance is NOT acceptable to us. Which means we spare no expense at putting together top-notch MWD kits.


That's why you'll find ONLY the best performing MWD tools in the entire industry in our fleet. The Native Navigation line of EM tools is consistently tested to 14,500 feet with signal headroom to spare. Our systems offer unmatched speed, reliability, and operational depth. By down-linking we can adjust virtually any parameter on the fly to adjust to conditions.


Data transmitted typically includes the inclination and azimuth angles of the borehole, the drilling system tool face (roll angle), and the tool temperature. The system can also be configured to transmit accelerometer and magnetometer sensor values, which can then be used to calculate the borehole angles.


At the top of the system, a non-magnetic drill collar with an electrically insulated gap sub is used. To generate electromagnetic signals that propagate to the surface, a low-frequency phase modulated signal is applied across the insulating gap. An upper electrode and the bolt in dipole head are used to apply the signal across the gap. The gap sub-signal is generated by the power driver electronics unit mounted in a pressure barrel just below the dipole head.


Typically, two 29V, 29 Amp-hour batteries encased in pressure barrels are used to power the electric dipole system, although the use of three or more batteries is possible for situations where high power output for a long period is required. The borehole angular orientation and drill string tool face are measured by a directional sensor mounted in a pressure barrel below the batteries. A gamma sensor is mounted directly below the system directional sensor.



  • Proven design with high reliability, MTBF over 2500 hours
  • Data transmission from depths of 14,000+ feet (4200+ meters) in favorable conditions
  • Real-time Annular Pressure & Drill Collar Internal Pressure
  • Rotation Sensing
  • Gamma Ray LWD



  • Reduce or eliminate Survey time – Typically ½ day to 1 day time savings per well
  • Underbalanced drilling
  • High-speed drilling where fast data rates are required
  • Low-pressure formations or lost circulation situations


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