旋转导向钻井工具近垂直姿态校正矩阵 误差的等角距均衡校正

旋转导向钻井工具中姿态校正方法的校正点本身包含各种系统误差，会引入校正矩阵误差，是近垂直姿态下姿态角解算精度低的原因之一.平均均衡校正方法(ABC)可补偿校正矩阵误差，但整体误差并不均匀.以等分角度间距设计校正点，建立一种等角距均衡校正(EABC)模型，推导校正矩阵误差表达式，研究其引起的姿态角误差特征.对多组近垂直姿态的测试数据分别进行传统校正、平均均衡校正和等角距均衡校正，结果表明：等角距均衡校正后，井斜角误差平均值均小于0.012°,井斜角误差峰峰值均小于0.027°;工具面角误差平均值均小于0.008°,工具面角误差的峰峰值和标准差分别降低到平均均衡校正的54%～95%和40%～63%,进一步提高垂直小井斜井段的姿态解算整体精度。

Equiangular interval balance correction of correction matrix error for rotary steering drilling tool under near-vertical position

The system errors of the rotary steering drilling tool are included in the designed points of the correction matrix. The correction matrix error occurs, which is one cause of low precision attitude angle under near-vertical position compensated by the traditional correction (TC) . Average balance correction (ABC) can compensate for the correction matrix error, but the posture error in the whole self-rotation cycle is still uneven. A kind of equiangular interval balance correction (EABC) model is formulated based on the equal angle interval, the expressions of correction matrix error are induced, those influence characteristics on the posture accuracy are investigated, and the experimental data are computed respectively with TC, ABC, and EABC. The computed results show that compensated by EABC, the average inclination angle errors are lower than 0. 012°, and the peak-to-peak inclination angle errors are lower than 0. 027°. The average tool face angle errors are lower than 0. 008°, the peak-to-peak tool faces angle errors are reduced to 54 ~ 95 percent of those by ABC, and the standard deviations of tool face angle error are decreased to 40 ~ 63 percent of those by ABC, which means that EABC further reduces the absolute error under near-vertical positions, then improves the attitude angle accuracy.