About Motors

The downhole drilling motor (or mud motor as it is sometimes called) is a hydraulically actuated device that converts hydraulic energy into mechanical energy.  The purpose of the motor is to generate the rotational speed (RPM) and torque needed to operate the drill bit.  The drilling motor takes its energy from a succession of isolated working fluid volumes that force their way, under pressure, through the motor by displacing or deforming the spaces in which they are confined.

An Introduction to Downhole Drilling Motors

The Toro motor is a positive-displacement motor (PDM).  As drilling fluid is pumped down the drill-string, the fluid flows through the cavities in the power section.  The fluid pressure reacts against the lobes of the rotor and the walls of the stator causing the rotor to rotate. Torque is then transmitted through the coupling section, bearing section and down to the drill bit.  The Toro drilling motor is comprised of 6 basic components:

  • Top Sub, which is used to connect the drilling motor to the drill string
  • Safety catch, which is used to removed the motor from the well in case of a failure
  • Power section, which provides the power to the downhole motor.  It consists of a rotor and a stator
  • Coupling section, where the energy from the power section is transmitted to the drill bit
  • Bearing section,  which controls the mechanical energy supplied by the power section to the drill bit
  • Bit Box, which is where the drill bit attaches to the motor.

Operators, drilling contractors, service, and tool supply companies have worked diligently over the years to improve drilling technology.  Their common goal has been to reach their drilling targets, quickly, efficiently, and at a reasonable cost.    Over the years, these drilling targets have become more complex and difficult to reach. Delivering horsepower directly to the bit has become increasingly important.  To date, the best way to achieve RPM and torque to the bit, independent of rotating the drill-string, is with a downhole drilling motor.

    Toro Downhole Tools
    16626  FM 292 Rd.
    Tomball, TX  77377