Research On The ADRC Technology Of Dynamic Point-the-Bit Rotary Steerable Drilling Tool

The dynamic point-the-bit rotary steerable drilling technology is currently the most advanced drilling technology,its dynamic performance and control effect of the stabilized platform determine the accuracy of the drilling direction control and the quality of the wellbore.In the harsh drilling conditions,such as high temperature,high pressure and strong vibration during the drilling process,the motor load disturbance is varied and the motor parameters are perturbed.The self-developed dynamic point-the-bit rotary steerable drilling tool(DPRSS)prototype was taken as the object,and the active disturbance rejection control(ADRC)technology and its application was used in this thesis.The main research contents and conclusions are listed as follows:i.The development status of rotary steerable drilling technology at home and abroad were introduced.The principles of various steerable products were analyzed.The advantages and research significance of DPRSS were clarified.ii.The working principle of the dynamic point-the-bit rotary steering drilling tool prototype was introduced,the control object of the DPRSS was clarified,and the measurement and control scheme has been designed.iii.The mathematic model of DPRSS was improved.On the basis of the structure of the control system,the tool face angle control scheme based on ADRC technology was determined by analyzing the stick-slip characteristics and interference.ADRC controller was optimized and used to control the permanent magnet synchronous motor(PMSM)speed and the tool face angle quickly and accurately.iv.The ADRC was applied to the simulation model and the prototypes' motor speed and position control of the stabilized platform.The load disturbance was simulated and tested under different working conditions.The ADRC has been compared with PID,and it was concluded that the ADRC has not only good dynamic performance,but also better anti-interference performance.v.The model-based ADRC was established.The motor speed loop and position loop of the stabilized platform are simulated and tested under different working conditions,the results showed that the performance index from model-based ADRC is significantly improved comparing with the common ADRC,especially in the stick-slip condition,the model-based ADRC can suppress the disturbance better.