Novick, Kim & Lee, PLLC
Near-bit tool attitude measurement while drilling apparatus and method
A near-bit tool attitude MWD apparatus includes measurement sensors and a measurement circuit. The measurement sensors transmit measured signals to the measurement circuit, and the measurement circuit processes and calculates the signals to obtain attitude data. The measurement sensors include a triaxial accelerometer, a triaxial gyroscope, a triaxial magnetic sensor and a temperature sensor, the measured data of the triaxial accelerometer, the triaxial gyroscope and the triaxial magnetic sensor are respectively corrected using the measured data of the temperature sensor, a first attitude angle is calculated using the corrected measured data of the triaxial accelerometer and the triaxial magnetic sensor. Quaternions are initialized using the first attitude angle, and the initialized quaternions are subjected to time updating according to the measured data of the triaxial gyroscope, and further an attitude angle is calculated utilizing the updated quaternions. The quaternions are periodically initialized to eliminate cumulative errors of the triaxial gyroscope, so as to improve the near-bit tool attitude MWD accuracy.
INSTITUTE OF GEOLOGY AND GEOPHYSICS, CHINESE ACADEMY OF SCIENCES
G E E E E
G01V E21B E21B E21B E21B
inventional additional inventional inventional additional
Yongyou Wenxuan Jian Wenxiu Yuntao Jianguang Qingyun
Yang Chen Zheng Zhang Sun Liu Di