Design Of Control System For Rotary Steerable Drilling Tool Model

As most onshore oilfields in China fell in the late development period,the drilling geological conditions became increasingly severe,and more complicated borehole structure increased the difficulty and cost of drilling,the technology of rotary steerable drilling became a research focus.Foreign companies had owned related commercial products,while domestic company is still in the stage of theoretical and experimental research.Based on the independent developed model of dynamic point-the-bit rotary steerable drilling tool,the signal detection,hardware design as well as control algorithm of its single axis stabilized platform have been studied.Firstly,the research status and the principle of rotary steerable drilling technology were introduced,the principle of sliding model control and its application,development were emphatically explained.Secondly,the principle of the rotary steerable drilling tool was briefly illustrated,and the principle and control strategy for the stabilized platform and steerable offset mechanism of our model of dynamic point-the-bit rotary steerable drilling tool were mainly introduced in detail.Thirdly,Allan variance was used to analyze and quantify the noise source of gyroscope signal,and Kalman filter was used to filter the gyroscope signal.The temperature drift of gyroscope signal was compensated based on experimental data.Fourthly,hardware of the stabilized platform control system was designed,including the control unit and the attitude detection unit.Finally,the mathematical model of the drilling tool model was established,and the sliding mode control algorithm was designed,simulated and tested.The experimental results showed that the sliding mode control algorithm was more suitable than PID controller both in dynamic response to step excitation and robustness to noise.