载体垂直姿态的非正交测量技术研究

发布时间：2018-12-17 22:24

【摘要】：在实时钻井中,准确测量井下姿态参数,(即井斜角I、工具面角T、方位角A)是实现井下全角度导向钻井的关键因素。采用正交坐标系时,传感器在垂直小角度附近输出的信号很微弱,经过AD采样和数值计算等后续处理后,误差仍很大,从而影响了参数计算精度。采用同类或不同类型传感器组合改进测量方法,建立各种误差模型补偿误差,均无法回避原始信号小的固有难题。本文对自动化钻井技术、国内外自动垂直钻井技术作了简要介绍,同时重点介绍了姿态更新算法中的方向余弦法。分析了姿态测量的基本原理,推导了采用石英挠性加速度计作为传感器的输出公式。研究了姿态测量参数的常规计算方法,分析了传统正交坐标系垂直姿态测量精度不足的内在原因。基于提高原始测量信号幅度及其信噪比的目的,提出一种非正交坐标系,研究了其理论模型和测量误差,并对其进行了理论验证。针对钻井过程中测斜仪各轴与理想坐标系各轴不重合引入的位置误差问题,提出一种系数补偿方法,对安装位置误差进行校正。实验结果表明,非正交坐标系在垂直姿态时可将原始信号幅度增强10倍以上,较大地提高了垂直姿态测量的总精度。采用系数补偿法对姿态参数校正后,各工具面角的实际数值与趋势线的估计值之间的拟合程度高。各井斜角的相对误差明显减小了,基本上实现了等精度,达到了较理想的校正效果。
[Abstract]:In real time drilling, accurate measurement of downhole attitude parameters (I. e., well inclination angle, tool face angle, azimuth angle A) is the key factor to realize downhole full angle guided drilling. When the orthogonal coordinate system is adopted, the signal output from the sensor near the vertical small angle is very weak. After AD sampling and numerical calculation, the error is still very large, which affects the accuracy of parameter calculation. Using the same or different sensor combination to improve the measurement method and to establish a variety of error models to compensate for errors can not avoid the inherent problem of small original signal. In this paper, the automatic drilling technology and automatic vertical drilling technology at home and abroad are briefly introduced, and the directional cosine method in attitude updating algorithm is emphasized. The basic principle of attitude measurement is analyzed, and the output formula of quartz flexible accelerometer is derived. The conventional calculation method of attitude measurement parameters is studied, and the inherent reasons for the deficiency of vertical attitude measurement accuracy in traditional orthogonal coordinate system are analyzed. In order to improve the amplitude of the original signal and its signal-to-noise ratio, a non-orthogonal coordinate system is proposed, its theoretical model and measurement error are studied, and its theoretical verification is carried out. In order to solve the problem of the position error caused by the inconsistency between each axis of the inclinometer and the axis of ideal coordinate system during drilling, a method of coefficient compensation is proposed to correct the position error of installation. The experimental results show that the amplitude of the original signal can be increased by more than 10 times in the non-orthogonal coordinate system in the vertical attitude, and the total accuracy of the vertical attitude measurement is greatly improved. After the attitude parameter is corrected by the coefficient compensation method, the fitting degree between the actual value of the tool face angle and the estimated value of the trend line is high. The relative error of the inclined angle of each well is obviously reduced, and the equal precision is basically achieved, and the ideal correction effect is achieved.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE24

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