1. Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029,China; 2. Key Laboratory of Coal Resources Exploration and Comprehensive Utilization, Ministry of Land and Resources, Xi'an 710054, China; 3. Shanxi Coal Geology No. 115 Exploration Institute, Datong 037003, China
Abstract：The electrical source short-offset transient electromagnetic method (SOTEM) has characteristics of strong signal, high resolution, large investigation depth, and less influence by topography and underground structure. It is therefore suitable for the detection of low resistivity body and fine structure. In addition, it is easily arranged and the receiving instrument is light and easy to operate, so it is very suitable for difficult field area with complex terrain. In this paper, the SOTEM method is analyzed theoretically, and the spatial distribution characteristics of the transient electromagnetic response of the layered geoelectric model in different time spans are calculated and simulated. The result shows the superiority of the near field observation. Based on the analysis of the relative error of response between different geoelectric models and the variation characteristics with the abnormal resistivity, the authors investigated the capability of SOTEM for discriminating electrical anomalies. In this paper, the authors have obtained the theoretical judgment formula of SOTEM detection depth, and put forward the commonly used formula of probing depth. At the end of this paper, the application of SOTEM to the detection of the gob in a coal mine in Datong of Shanxi Province is given to illustrate the effectiveness of the method. According to the comparison, the detection results coincide with the drilling information.
卢云飞, 薛国强, 邱卫忠, 周楠楠, 侯东洋. SOTEM研究及其在煤田采空区中的应用[J]. 物探与化探, 2017, 41(2): 354-359.
LU Yun-Fei, XUE Guo-Qiang, QIU Wei-Zhong, ZHOU Nan-Nan, HOU Dong-Yang. The research on SOTEM and its application in mined-out area of coal mine. Geophysical and Geochemical Exploration, 2017, 41(2): 354-359.
 薛国强,陈卫营,周楠楠,等.接地源瞬变电磁短偏移深部探测技术[J].地球物理学报,2013,56(1):255-261.  Jackson D B,Keller G V.An electromagnetic sounding survey of the summit of Kilauea Volcano,Hawaii[J].Journal of Geophysical Research,1972,77(26):4957-4965.  Skokan C K.A time-domain electromagnetic survey of the East Rift Zone,Kilauea Volcano,Hawaii[D].Golden Colo:Colorado School of Mines,1974.  Keller G A,Rapolla A.Electrical prospecting methods in volcanic and geothermal environments[C]//Civetta L,Gasparini P,Luongo G,et al.Physical Volcanology.Amsterdam:Elsevier,1975:133-166.  Sternberg B K.Electrical resistivity structure of the crust in the southern extension of the Canadian shield-layered earth models[J].Journal of Geophysical Research:Solid Earth,1979,84(B1):212-228.  Lienert B R.Crustal electrical conductivities along the eastern flank of the Sierra Nevadas[J].Geophysics,1979,44(11):1830-1845.  Kauahikaua J.Electromagnetic fields about a horizontal electric wire source of arbitrary Length[J].Geophysics,1978,43(5):1019-1022.  Harthill N.Time-domain electromagnetic sounding[J].IEEE Transactions on Geoscience Electronics,1976,14(4):256-260.  Hordt A,Muller M.Understanding LOTEM data from mountainous terrain[J].Geophysics,2000,65(4):1113-1123.  Strack K M.Exploration with deep transient electromagnetics[M].New York:Elsevier,1992.  严良俊,胡文宝,陈清礼,等.长偏移距瞬变电磁测深法在碳酸盐岩覆盖区落实局部构造的应用效果[J].地震地质,2001,23(2):271-276.  廖忠,李文尧.线源TEM在腾冲热水塘寻找地热的应用效果[J].工程勘察,2002(1):67-69.  Rabinovich B I.Comparative evaluation of sounding by transient fields in the far and near zones[J].Geologiya i Geofizika,1978,11:148-152.  Goldman M M,Grekova L B,Morozova G M,et al.Album of two-layer sounding curves for the transient horizontal magnetic field in the near zone[J].Akad Nauk SSSR,1976(9).  Antonov Y N,Manshtein A K.Development of equipment for depth sounding with transient field in the near zone (ZCB)[C]//Theory and Use of electromagnetic Fields in Exploration Geophysics.Novosibirsk:Akademiia Nauk SSSR,1979:18-26.  Azad J.Mapping stratigraphic traps with electrical transients[J].Bulletin of Canadian Petroleum Geology,1977,25(5):995-1036.  Gonzalez J M S.Test of time-domain electromagnetic exploration for oil and gas[D].Colorado:Colorado School of Mines,1979.  Cuevas N H, Alumbaugh D. Near source response of a resistive layer to vertical electric dipole excitation[C]//SEG Houston 2009 International Expanded Annual Meeting, 2009: 794-798.  Ziolkowski A M.Short-offset transient electromagnetic geophysical surveying[P].US,EP2219050,2010-08-18.  Cuevas N H,Alumbaugh D.Near-source response of a resistive layer to a vertical or horizontal electric dipole excitation[J].Geophysics,2011,76(6):F353-F371.  Um E S,Alumbaugh D L,Harris J M,et al.Numerical modeling analysis of short-offset electric-field measurements with a vertical electric dipole source in complex offshore environments[J].Geophysics,2012,77(5):E329-E341.  Xue G Q,Gelius L J,Sakyi P A,et al.Discovery of a hidden BIF deposit in Anhui province,China by integrated geological and geophysical investigations[J].Ore Geology Reviews,2014,63:470-477.  Zhou N N,Xue G Q,Chen W Y,et al.Large-depth hydrogeological detection in the North China-type coalfield through short-offset grounded-wire TEM[J].Environmental Earth Sciences,2015,74(3):2393-2404.  Chen W Y,Xue G Q,Muhammad K H,et al.Application of short-offset TEM (SOTEM) technique in mapping water-enriched zones of coal stratum,an example from east China[J].Pure and Applied Geophysics,2015,172(6):1643-1651.  Kaufman A A,Keller G V.Frequency and transient soundings[M].Amsterdam:Elsevier Science Publishers,1983.  Spies B R.Depth of investigation in electromagnetic sounding methods[J].Geophysics,1989,54(7):872-888.  朴化荣,殷长春.频率测深水平磁场的正演计算及应用[J].物探化探计算技术,1988,11(3):204-213.  Zhou N N,Xue G Q.The ratio apparent resistivity definition of rectangular-loop TEM[J].Journal of Applied Geophysics,2014,103:152-160.