自动垂直钻井中井斜动态测量理论与实验研究

井斜动态测量是指在钻井过程中对井眼的井斜角、工具面角等物理量的实时检测和信息的提取,比静态测量复杂,钻具的振动和转动均会导致相应的井斜测量信号严重失真,但其中的振动信号可用低通滤波器滤除,而钻具转动对加速度计所产生的离心力导致的测量信号的失真,则必须通过诸如转速补偿之类的修正才能去除.低通滤波器可选用一定阶数和转折频率的巴特沃斯滤波器,而加速度计输出的转速补偿则须预先对加速度计进行标定.利用专门的实验装置对井斜动态测量的方法及其具体实现进行了有效的验证.

Theoretical and experimental investigation on dynamic measurements of hole inclination in automatic vertical drilling process

The dynamic measurement of hole inclination is one of the key techniques for the anti-deviation control of automatic vertical drilling. The key of this technique is to pick up information of hole inclination and corresponding direction of hole deflection using gravity accelerometer sensors during drilling. The dynamic measurement of hole inclination is more complex than the static measurement. The measured data may be distorted seriously under the vibration and rotation of drill string. However, the vibration noises can be eliminated from the inclination measurement by low-pass filter. The centrifugal force caused by rotation of drilling tool will distort the accelerometer outputs, which can only be revised by rotation speed compensation. The methods for selecting low-pass filter and error compensation of accelerometer outputs were proposed and proved by experiments.