|
|
A numerical study of transient electromagnetic sounding effect using the induced voltage and the B field data |
LI Zhan-Hui1( ), YANG Miao-Xin2, CAO Xue-Feng1 |
1. China Aero Geophysical Survey and Remote Sensing Center for Natural Resources, Beijing 100083, China 2. Hebei Key Laboratory of Strategic Critical Mineral Resources, Hebei GEO University, Shijiazhuang 050031, China |
|
|
Abstract In this study, the authors compared the loop source transient electromagnetic sounding effect between the induced voltage data and Bz data obtained by one-dimensional and three-dimensional forward modelling. The longest effective delay time of the two types of data under the current data acquisition accuracy of mainstream hardware was analyzed through a comparison of multiple models; the longitudinal and horizontal resolutions of the two types of data were analyzed through a comparison of apparent conductivity and one-dimensional inversion. The results show that, under the data acquisition accuracy presumed in this study, only when an abnormal body with a conductivity ≥ 0.036 S/m exists in the model can the effective delay time of the Bz data be longer than the induced voltage data. Compared with the induced voltage data, the Bz data can sense the underground anomaly in advance, but are worse in longitudinal and horizontal resolutions. The recovery of resistivity by Bz data is also worse than that by the induced voltage data. In the actual field measurement, it is not recommended to record only the Bz field. If conditions are allowed, the induced voltage and the Bz field could be collected simultaneously to obtain an optimized solution.
|
Received: 26 February 2020
Published: 01 March 2021
|
|
|
|
|
[1] |
Ward S H, Hohmann G W. Electromagnetic theory for geophysical application[C]// SEG:Electromagnetic Methods in Applied Geophysics, 1987.
|
[2] |
崔江伟, 薛国强, 陈卫营, 等. 电性源瞬变电磁B场全程视电阻率计算[J]. 地球物理学进展, 2015,30(6):2690-2697.
|
[2] |
Cui J W, Xue G Q, Chen W Y, et al. Calculation of all-time apparent resistivity for B field due to electrical source TEM[J]. Progress in Geophysics, 2015,30(6):2690-2697.
|
[3] |
王兴春, 张杰, 郑学萍, 等. 磁通门探头在瞬变电磁法勘探中的应用[J]. 物探化探计算技术, 2014,36(6):649-654.
|
[3] |
Wang X C, Zhang J, Zheng X P, et al. Application of fluxgate sensor in TEM prospecting[J]. Computing Techniques for Geophysical and Geochemical Exploration, 2014,36(6):649-654.
|
[4] |
Ji Y J, Du S Y, Xie L J, et al. TEM measurement in a low resistivity overburden performed by using low temperature SQUID[J]. Jounral of Applied Geophysics, 2016,135:243-248.
|
[5] |
荣亮亮, 蒋坤, 裴易峰, 等. 适用于瞬变电磁勘探的低温超导磁传感器[J]. 仪器仪表学报, 2016,37(12):2672-2677.
|
[5] |
Rong L L, Jiang K, Pei Y F, et al. Low-Tc SQUID sensor for time domain electromagnetic prospecting[J]. Chinese Journal of Scientific Instrument, 2016,37(12):2672-2677.
|
[6] |
陈晓东, 赵毅, 张杰, 等. 高温超导磁强计在瞬变电磁法中的应用研究[J]. 地球物理学报, 2012,55(2):702-708.
|
[6] |
Chen X D, Zhao Y, Zhang J, et al. The application of HTc SQUID magnetometer to TEM[J]. Chinese Journal of Geophysics, 2012,55(2):702-708.
|
[7] |
Thomson S, Fountain D, Watts T. Airborne geophysics-evolution and revolution[C]// 5th Decennial International Conference on Mineral Exploration, 2007.
|
[8] |
Smith R, Annan P. The use of B-field measurements in an airborne time-domain system: Part I. Benefits of B-field versus dB/dt data[J]. Exploration Geophysics, 1998,29:24-29.
|
[9] |
Smith R, Annan P. Using an induction coil sensor to indirectly measure the B-field response in the bandwidth of the transient electromagnetic method[J]. Geophysics, 2000,65(5):1489-1494.
|
[10] |
Wolfgram P, Thomson S. The use of B-field measurements in an airborne time-domain system-Part II: examples in conductive regimes[J]. Exploration Geophysics, 1998,29:225-229.
|
[11] |
强建科, 罗延钟, 汤井田, 等. 航空瞬变电磁法的全时域视电阻率计算方法[J]. 地球物理学进展, 2010,25(5):1657-1661.
|
[11] |
Qiang J K, Luo Y Z, Tang J T, et al. The algorithm of all-time apparent resistivity for Airborne Thransient Electromagnetic (ATEM) survey[J]. Progress in Geophysics, 2010,25(5):1657-1661.
|
[12] |
Li Z H, Huang Q H, Xie X B, et al. A generic 1D forward modeling and inversion algorithm for TEM sounding with an arbitrary horizontal loop[J]. Pure and Applied Geophysics, 2016,173(8):2869-2883.
|
[13] |
Wang T, Hohmann G W. A finite-difference, time-domain solution for 3-dimensional electromagnetic modeling[J]. Geophysics, 1993,58(6):2105-2114.
|
[14] |
邱稚鹏, 李展辉, 李墩柱, 等. 基于非正交网格的带地形三维瞬变电磁场模拟[J]. 地球物理学报, 2013,56(12):4245-4255.
|
[14] |
Qiu Z P, Li Z H, Li D Z, et al. Non-orthogonal-grid based three dimensional modeling of transient electromagnetic field with topography[J]. Chinese Journal of Geophysics, 2013,56(12):4245-4255.
|
[15] |
李展辉, 黄清华. 复频率参数完全匹配层吸收边界在瞬变电磁法正演中的应用[J]. 地球物理学报, 2014,57(4):1292-1299.
|
[15] |
Li Z H, Huang Q H. Application of complex frequency shifted perfectly matched layer absorbing boundary conditions in transient electromagnetic method modeling[J]. Chinese Journal of Geophysics, 2014,57(4):1292-1299.
|
[16] |
周建美, 刘文涛, 李貅, 等. 双轴各向异性介质中回线源瞬变电磁三维拟态有限体积正演算法[J]. 地球物理学报, 2018,61(1):368-378.
|
[16] |
Zhou J M, Liu W T, Li X, et al. Research on the 3D mimetic finite volume method for loop-source TEM response in biaxial anisotropic formation[J]. Chinese Journal of Geophysics, 2018,61(1):368-378.
|
[17] |
戴锐, 李展辉, 黄清华. 瞬变电磁法三维模型数据的一维反演效果研究[J]. 地球物理学进展, 2017,32(3):1121-1129.
|
[17] |
Dai R, Li Z H, Huang Q H. Study of one-dimensional inversion effect on transient electromagnetic data of three-dimensional models[J]. Progress in Geophysics, 2017,32(3):1121-1129.
|
[1] |
ZHANG Fan, FENG Guo-Rui, QI Ting-Ye, YU Chuan-Tao, ZHANG Xin-Jun, WANG Chao-Yu, DU Sun-Wen, ZHAO De-Kang. Feasibility of the transient electromagnetic method in the exploration of double-layer waterlogged goafs with different layer spacings in coal mines[J]. Geophysical and Geochemical Exploration, 2023, 47(5): 1215-1225. |
[2] |
ZHOU Zhong-Hang, ZHANG Ying-Ying. Correction of the influence of mountains on grounded-source transient electromagnetic responses[J]. Geophysical and Geochemical Exploration, 2023, 47(5): 1236-1249. |
|
|
|
|