The Downhole Screw Motor is a kind of power tool that transforms the pressure of liquid to mechanical energy in the downhole. When the power liquid flows into the screw motor, pressure difference will be produced between the inlet and outlet of the motor, then the pressure difference drives the rotor rotating of planetary motion round the stator, and provides turning torque and speed to the drill bit. The Downhole Screw Motor is suitable for vertical, directional and horizontal wells.
Characteristics and Advantages of Downhole Screw Motors:
The torque generated by the screw motor only turns the drill bit, which can dramatically decrease drill pipe wear.
The screw motor can be incorporated into special BHA to realize high built-up rate or screwed to orientating tool to perform continuously controlled kick-off.
Output torque of the screw motor is in linear relationship with drilling fluid differential pressure generated by the hydraulic motor.
Screw motor with hollow rotor allows for large flow rate, which then leads to accelerated flowback speed and sand carrying capacity.