Research On The ADRC Technology Of Rotary Steerable Drilling Tool

Rotary steerable drilling represents the development direction of high precision steerable drilling technology.The core component of the steerable drilling tool is the stable platform,whose control precision and anti-disturbance ability determine the drilling direction of the bit and the quality of the wellbore.Due to the existence of high temperature and high pressure,stick-slip and other disturbances in the drilling process,the control accuracy of drilling tools is affected.The prototype of dynamic point-the-bit rotary steerable drilling tool(DPRSS)was the research object,the active disturbance rejection control(ADRC)technology was used to improve the anti-disturbance ability of drilling tool.The main contents and conclusions of the research are as follows:Firstly,the basic principle of rotary steerable drilling system,classification and working principle of steerable drilling tools were introduced.The research status of servo control and ADRC technology of stabilized platform of steering drilling tools at home and abroad were analyzed.,and the research significance of the DPRSS was illustrated.Secondly,the overall structure,working principle,measurement and control requirements of the DPRSS were described.Based on the analysis of various disturbances in the control system of the stabilized platform,the measurement and control scheme of the stabilized platform for drilling tools was proposed.Thirdly,based on the mathematic model of stabilized platform of the DPRSS,the current loop ADRC controller for servo motor was designed.Through simulation analysis and experimental test,it was verified that the ADRC current loop of stabilized platform servo motor could effectively suppress the model uncertainty,dead zone effect.Fourthly,the basic principle of Kalman state observer was introduced.According to the model of control system,the Kalman state observer was designed.The observed load torque was used to design ADRC controller of the speed loop.The results of simulation and experiment showed that this algorithm can suppress the fluctuation of load torque well.Finally,aiming at stick-slip disturbance of drilling tools,a model-based nested ESO ADRC(MNADRC)was proposed in order to control tool face angle.Simulation and experimental tests were carried out under stick-slip and different drilling modes,and the control effects were compared and analyzed.Compared with conventional ADRC,MNADRC has the best anti-disturbance effect,followed by nested ESO ADRC(NADRC).MNADRC and NADRC can meet the requirements of drilling engineering index.