Downhole motor is a kind of downhole dynamic drilling tool drove by the hydraulic power of drilling mud, and its core power part is a positive displacement motor. The tool is with simple structure, convenient operation and reliable performance. The tool can be drove by the power fluid, such as oil-based mud, emulsion mud and clay mud, is adaptable and flexible, and can be applied to horizontal wells, cluster wells particular drilling operations, that can greatly increase the drilling speed and economic benefits.

        With mud, water as the driving force media transported to the Downhole Motor through the center hole of drill string, the downhole motor is essentially a kind of energy conversion device which converts liquid pressure energy to mechanical energy. When drilling, the Downhole Motor directly drives the drill bit connected to the drive shaft to slew. The whole drill string is only as a transport channel delivering high-pressure working medium and the drill rod(pipe) member supporting drill bit counter-torque, and do not slew. Compared with the conventional drilling operation, the drilling operation with Downhole Motor has many advantages, such as drill pipes wear dropped substantially, high speed, etc. Downhole Motor is the main tool to drill directional wells, has played a significant role in the drilling fields.

        Compared with the traditional drilling operation that the drill pipes are driven by turntable, the drilling operation with Downhole Motor has many advantages as following:
■ The drilling fluid input flow is proportional to the downhole motor output speed.
■ Downhole motor output torque is linearity relation with pressure drop produced by drilling fluid through the motor. 
■ Lower downhole motor output speed, greater torque, and longer net drilling time.
■ Downhole motor is adopted a group of multi-column thrust radial ball bearing, resistance to high pressure, and high penetration rate. 
■ Downhole motor is adopted insert welded tungsten carbide transverse bearing, long service lift. 
■ Pressure drop of drill bit nozzle is up to 7.0MPa, high horsepower of drill bit hydraulic, rinse drill bit clean to prevent drill bit balling.
■ Downhole motor rotary power is only used to drive the drill bit to reduce the drill pipe wear, streamline operations, improve drilling accuracy, and saving drilling power.
■ In directional drilling operations, the Downhole Motor is easier to control the direction of the borehole, can be reduced more drilling deviation than the conventional rotary drilling.