The Solenoid Pulser generates a sequence of pressure increment pulses in the circulating system, enabling the transmission of MWD data recorded downhole to surface.


The tool is fully retrievable and replaceable, saving rig time by eliminating pipe trips for directional equipment.

The Tensor solenoid pulser design consists of an oil-filled pulser section and an electronic driver section.  The driver section contains a large multi-capacitor bank that stores energy from the battery packs and is controlled by the timing/switching circuitry to generate time pulses.  This section is connected to the oil-filled section containing a double solenoid attached via spring loaded shafts to the servo poppet.  A pulse is generated when a pulse signal sent by the directional module to the pulser driver and releases energy from the capacitor bank to the solenoid assembly.  The energy activates both the “pull-in” solenoid and the “holding” solenoid.

The method associated with the reproducible pulses occurs when a pulser is manipulated in an upward and downward direction by a combination of the solenoid activation of a bidirectional poppet (to redirect the fluid flow from the pressure reservoir to and from a sliding pressure chamber) and associated upper and lower flow channels.

The valve is urged toward a closed position by drilling fluid pumped through the drill string. A larger force is required to open the valve than to hold it open. Current supplied to the solenoid to open the valve is thereafter reduced to a value sufficient to hold the valve open. The solenoid is de-energized to close the valve, completing the generation of the mud pulse.

solenoid pulser


  • Simple to operate under a wide range of flow rates
  • Operable in lost circulation material concentrations of 10 lb/bbl medium nut plug
Min Flow Rate 75 gpm (8 L/sec)
in water
Max Flow Rate 1,100 gpm (67 L/sec) in water
Max Operating Temp 175°C (350°F)
Max Hydrostatic Pressure 20,000 PSI (137.9 MPa)
Operating Voltage 20-29 V
Nominal Current 24 mA
Shock 1,000 g / 0.5 ms
Vibration 25g RMS 30-500 Hz Random

30g 50-300 Hz Sine
Mud Sand Content <1% recommended
Poppet Force (Push/Pull) Open & Close Force 75 lbs