物探与化探2025，Vol.49Issue(2)：360-369,10.DOI:10.11720/wtyht.2025.2486
复杂形态回线源的地—井瞬变电磁多分量响应特征分析
Analysis of multi-component response characteristics of surface-to-borehole transient electromagnetic method with complex-shaped loop source
摘要
Abstract
In actual exploration,the surface-to-borehole transient electromagnetic(TEM)method is prone to be affected by irregular transmitter loops and inclined boreholes,resulting in increased measurement errors of the three-component induced magnetic fields and decreased interpretation accuracy.By establishing surface-to-borehole TEM method-based three-component measurement models under the excitement of transmitter loops of various shapes,this study derived the calculation formulas for surface-to-borehole TEM responses under inclined boreholes through coordinate transformation.Then,it achieved one-dimensional forward modeling of the full-space TEM field using a numerical filtering algorithm.The calculation results of multiple typical models indicate that the three components of the transient magnetic fields were significantly influenced by the shapes of the transmitter loops,with the impacts on horizontal components x and y far more significant than those on vertical component z.The transmitter loops of regular polygons with even edges as the sources exhibited uniform and symmetric distribution of the TEM fields of the three components.Under the condition of the same perimeter,a greater number of edges of the transmitter loops associated with greater primary field energy excited by the loops.Therefore,rectangular transmitter loops as the sources prove the most cost-effective.The inclination and offset primarily affected the amplitude of the three-component responses.In contrast,the borehole azimuth mainly influenced the sign of the horizontal components,bearing rich informa-tion on location.Therefore,in the exploration using the surface-to-borehole TEM method,it is necessary to accurately determine source paths and the geometric morphologies of boreholes to make essential corrections,thus improving the accuracy and reliability of interpre-tations.关键词
地—井瞬变电磁法/三分量响应/响应特征/发射场源Key words
surface-to-borehole transient electromagnetic method/three-component response/response characteristic/transmitting source分类
天文与地球科学引用本文复制引用
王志鑫,邓居智,陈辉,邱长凯,余辉,尹敏,冯敏..复杂形态回线源的地—井瞬变电磁多分量响应特征分析[J].物探与化探,2025,49(2):360-369,10.基金项目
国家自然科学基金项目(42104081、42130811、41864004) （42104081、42130811、41864004）
江西省主要学科学术带头人培养计划项目(20204BCJL23058) （20204BCJL23058）
自然资源部深地科学与探测技术实验室开放课题(Sinoprobe Lab 202214) （Sinoprobe Lab 202214）
