Rotary steerable drilling system is one of the most important equipment in oil drilling field now, and it is a combination of mechanical, electrical, hydraulic, information and control technologies. It can execute steerable drilling with the help of MWD or LWD at the near-bit end. This equipment is the core technique and crucial to realize the digitization, informatization, automation of the oil drilling, and it is widely used for the steerable drilling of ground and offshore wells such as ultra-deep wells, horizontal wells, extended reach wells, and branch wells, etc.

Rotary steerable drilling system consists of various subsystems including power generation, power transmission, mechanical, motor, hydraulic, positioning and measurement. During drilling, the drilling mud well supply the generator the power for generating electricity to the whole steerable drilling system. The control pad collects pressure, deviation and signals from the ground for data analysis, and sends instructions to the actuator. After receiving the instructions, the hydraulic system of the motor pump will control the extension and drawback movement of the steerable ribs, then the well wall is forced from different directions, and the steerable drilling is realized via the control of the three steerable ribs.