ZHAO Yu-Gang1, XUE Guo-Qiang2,3, HUANG Shen-Shuo1, LU Zhan-Guo1, CUI Jiang-Wei2,3, HOU Dong-Yang2,3
1. Beijing Orangelamp Geophysical Exploration Co., Ltd., Beijing 102200;
2. Key Laboratory of Mineral Resources, Chinese Academy of Science, Beijing 100029;
3. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029
In normal TEM sounding,the parameter of secondary induced voltage V signal is collected by using magnetic induced coil;however,the late signal is usually too weak to identify deep buried target.In this paper,direct measuring of B field parameters is used to test its practical effect.Firstly,from the response of B field and dB/dt and numerical calculation of different models,we can see that the B field has superiority in late time detection.Then the SM24 TEM system which is used to measure B field and the GDP-32 system which is adopted to measure induced voltage are compared with each other.With the same observation parameters,B field data are more superior than induced voltage data.The characteristic frequency of fluxgate sensor is relatively low and it decays slow.In addition,the amplitude of B field data is larger than that of dB/dt data.This means is favorable for measurement in late time because the influence of low resistivity covered layer on it is relatively low.The results show that developing and using fluxgate sensor is an important direction to resolve fine TEM exploration.
赵育刚, 薛国强, 黄申硕, 陆占国, 崔江伟, 侯东洋. 瞬变电磁B场参数测试效果[J]. 物探与化探, 2016, 40(1): 174-178.
ZHAO Yu-Gang, XUE Guo-Qiang, HUANG Shen-Shuo, LU Zhan-Guo, CUI Jiang-Wei, HOU Dong-Yang. Test and analysis of TEM B field parameter. Geophysical and Geochemical Exploration, 2016, 40(1): 174-178.
[1] 蒋邦远.实用近区磁源瞬变电磁法勘探[M].北京:地质出版社,1998.[2] 李貅,薛国强.瞬变电磁法拟地震偏移成像研究[M].北京:科学出版社,2013.[3] 牛之琏.时间域电磁法原理[M].长沙:中南大学出版社,2007.[4] Levy G M.Correction of measured transient electromagnetic responses for finite transmitter turn-off duration[M].1984.[5] Mc Cracken K G,Oristaglio M L,Hohmann G W.A comparison of electromagnetic exploration systems[J].Geophysics,1986,51(3):810-818.[6] Sarma D G,Maru V M,Varadarajan G.An improvedbpulse transient airborne electromagnetic system for locating goodv conductors[J].Geophysics,1976,41(2):287-299.[7] Eaton P A,Hohmann G W.An evaluation of electromagnetic methods in the presence of geologic noise[J].Geophysics,1987,52(8):1106-1126.[8] Smith R S,Annan A P.The use of B field measurements in an airborne time-domainsystem Part I:Acomparison of B field with dB=dt measurements[J].Exploration Geophysics,1998,29(3):24-29.[9] 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(5):225-229.[10] Duckworth K,O'Neill D.Detection of a brine conductor under an oil field by means of a fixed transmitter electromagnetic survey using a squid magnetometer[J].Exploration Geophysics,1989,25(1):61-73.[11] Richard Smith,Peter Annan.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.[12] James.Experience with SQUID magnetometers in airborne TEM surveying Exploration[J].Geophysics,2002,67(2):009-013.[13] 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.[14] 王赤军,陈晓东,赵毅,等.77K SQUID磁强计在TEM测量上的应用研究[J].地球物理学报,1999,41(S1):161-166.[15] 李貅.瞬变电磁测深的理论与应用[M].西安:陕西科学技术出版社,2002.