Research on the Calibration Method of Vibration Error of Accelerometer Gyroscope for Guided Drilling Near-Drill Bit

Problems such as attitude solution abnormality and trajectory deviation occur in the process of guided drilling in horizontal wells; in essence, the near-drill bit inclinometer is affected by the complex vibration generated by the drill bit when it rotates and breaks the rock, which leads to a large amount of interference noise in the measured values of accelerometers and gyroscopes and seriously affects the accuracy of the drilling tool attitude measurement. To address the problem that the near-drill accelerometers and gyroscopes in different attitudes of guided drilling contain a large amount of complex rotational vibration noise, this article proposes a dynamic Allan variance-assisted extended Kalman filtering method for the gyroscope measurement error, and proposes an adaptive untraceable Kalman filtering method that introduces a triangular component for the accelerometer measurement error. First, the measurement error characteristics of gyroscope and accelerometer under rotational vibration interference are analyzed, and the DAVAR is used to model the measurement error of gyroscope. This model is integrated into EKF, so as to inhibit the nonlinear measurement error of gyroscope. Second, for the measurement error characteristics of accelerometers under complex vibration, the measurement error model is established, an adaptive traceless Kalman filter based on this model and the triangular component into the AUKF to assist it in selecting the sigma point when filtering in the transverse and tangential axes, so as to improve the filtering effect. Third, the quaternion method is used to solve the attitude of the processed angular velocity as well as acceleration to further verify the feasibility of the above filtering method. Finally, the software and hardware experimental platform for near-drill accelerometer gyroscope vibration error calibration is constructed, and the experimental results show that the angular velocity error is controlled within the range of ±0.5 deg/s, and the acceleration error is controlled within the range of ±0.6 m/s2. The calculated inclination accuracy is better than ±0.2°, the calculated tool face accuracy is better than ±0.3°, and the dynamic measurement error of the near-drill bit caused by vibration is effectively suppressed.