Research On Multi-sensor Combined Measurement Method For Steering Drilling Tool

The attitude measurement of rotary steering drilling tool is the key to steering control,and the attitude parameters required for steering control mainly include inclination,toolface angle and revolving speed etc.Accurate and real-time measurement of these parameters is a prerequisite for drilling tools to achieve steering control.However,the high-speed rotation of the drilling tool,the strong vibration near the drill bit,and the interference magnetic field around the drilling tool inevitably mixture a large number of interference noises to the output signals of the inertial accelerometer and the fluxgate sensors,resulting in serious distortion of the attitude parameters.Aiming at the above problems,a multi-sensor combined method of attitude measurement for steering drilling tool is proposed.Finally,the simulation and vibration experiments show that the correctness and effectiveness of our method.The main research results are as follows:1^st.The problem that the drilling tool attitude parameters are severely distorted under the conditions of rotation,vibration and interference magnetic filed is studied.To this issue,a speed compensation method and a hard magnetic compensation method are used to eliminate the influence of rotation and interference magnetic filed on the attiude measurement;a multi-sensor WLS weighted fusion method is put forword to effectively filter out the vibration interference signal in the accelerometer.2^nd.Base on the drilling tool attitude measurement system constructed by a three-axis inertial accelerometer,a three-axis fluxgate sensor,and an angular rate gyroscope,a multi-sensor combination measurement method is proposed.When the inclination is 0.3degrees,numerical simulation analysis shows that the maximum solution errors of the calculated inclination and toolface angle are 0.05 degree and 20 degree,respectively.The above simulation results show that this method is correct and effective.3^rd.According to the design requirements of the tool attitude measurement system,the design and debugging of the system hardware circuit is completed,with the corresponding software programming at the same time.Finally,an attitude measurement device for steering drilling tool is made.4^th.Simulation experiments under multiple vibration modes show that the multi-sensor combined measurement method can effectively eliminate the influence of vibration and interference magnetic field on attitude measurement.Especially,at 1.5 degrees inclination,the maximum solution error of inclination and toolface angle are 1.8 degree and 28 degree,respectively.Its calculation error is greatly reduced compared with before this method not used,which shows that this method can effectively solve the problem of dynamic measurement of tool attitude and improve the dynamic measurement accuracy.These research results can provide a useful reference for further research on the dynamic measurement method of the attitude for the steering drilling tool.