煤矿地孔瞬变电磁巷道超前定位方法

电磁法超前通过巷道数据预报前方100m距离内含水体，是保障煤矿防治水安全的常规手段。随着采掘技术不断进步，对超前结果提出距离更远、结果更准的要求。受巷道复杂环境与工作方式限制，当前技术难以根本性提升。研究发现，地面激发、地下接收的瞬变电磁法具有装置优势，能解译目标内部多参数。项目利用超前长钻孔建立地面激发、孔中接收的观测装置，以等效电流环理论为基础反演目标体内部涡流中心位置、尺寸、姿态等多个参数，实现前方含水体长距离空间定位。主要研究内容包括：以钻孔大数据为基础建立煤田含水体地质与地电模型，掌握地孔瞬变电磁三分量响应机理；基于Z分量一维反演与相关分析实现弱异常场与强背景场分离；论证含水体涡流场与电流环辐射场等效性，结合三分量指向性和电流环反演，实现含水体三维空间定位算法。项目利用超前钻孔形成新的观测方式，实现“一孔多用”并突破“一孔之见”，提高超前探水准确性和工作效率，契合煤矿生产要求。

The electromagnetic method in advanced detection achieves the purpose of predicting the water content within 100m by collecting data in front of the face of the roadway. It is a conventional means to ensure coal mine water prevention and control. As mining technology continues to advance, the results of advanced detection require farther distances and more accurate. Due to the complex environment of the roadway and working methods of advanced detection, it is difficult to obtain a fundamental improvement in current technology. The study found that the ground-excited, underground-receiving transient electromagnetic method has the advantage of interpreting the multi-parameters within the target. The project uses the advanced long borehole in front of the face to establish the observation device which is ground-excited and received in the hole. Based on the equivalent current loop theory, several parameters of the internal vortex center position, size and attitude are inverted to realize the long-distance spatial positioning of the front water body. The main research contents include: establishing geological and geoelectric model of coal-bearing water body based on borehole big data in order to master the three-component response mechanism of ground-hole transient electromagnetic; achieving the separation of weak anomaly field and strong background based on Z-component one-dimensional inversion and correlation analysis; demonstrating the equivalence of eddy current field and current loop radiation field in water body, combined with three-component directivity and current loop inversion to realize three-dimensional spatial localization algorithm of water body. The project uses advanced drilling to establish a new way of observation to achieve ‘one hole multi-use’ and break through the ‘one hole single message’, which can improve the accuracy of forward water exploration and work efficiency to meet the coal mine production requirements.