磁短节等效磁矩的测量

Measurement of magnetic sub equivalent moment

刁斌斌 高德利 吴志永

DIAO Binbin GAO Deli WU Zhiyong

中国石油大学石油工程教育部重点实验室，北京　102249

MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, China

旋转磁场测距导向系统是一种精确探测邻井距离的新技术，在复杂结构井钻井工程中正发挥越来越重要的作用。磁短节在钻井现场地表的等效磁矩是判断旋转磁场测距导向系统测量结果可信度的重要依据之一，磁短节等效磁矩的测量是旋转磁场测距导向系统作业中的关键环节之一。根据磁偶极子周围空间磁场分布规律，推导了旋转磁短节周围空间远场的磁场分布规律，给出了磁短节等效磁矩的间断测量法和磁短节等效磁矩的连续测量法，并对这两种测量方法操作的难易程度和影响测量精度的主要因素进行了初步探讨。研究结果表明，磁短节等效磁矩的连续测量法具有影响因素少、测量精度高及操作简单的特点，更易于现场应用。

The Rotating Magnet Ranging System is a new technique for accurately detecting the distance between adjacent wells, and it is taking more and more important roles in drilling wells with complex structure. The equivalent magnetic moment of the magnetic sub is one of the important indicators for assessing the measurement reliability, and the measurement of the equivalent magnetic moment is one of the key parts during the working of Rotating Magnetic Ranging System. On the basis of the magnetic field distribution around the magnetic dipole, the far-field magnetic field distribution around the rotating magnetic sub is derived. The discontinuous measurement method and the continuous measurement method for magnetic sub equivalent moment are obtained, and the complexity and factors affecting measurement accuracy of the two measurement methods are preliminarily discussed. The result indicates that the continuous measurement method for magnetic sub equivalent moment is easier to handle and has less influence factors and a higher precision, so it is easier to be practically applied than the discontinuous measurement method.