,556 北京科技大学学报 第29卷 经过大量实测资料验证,系统可以达到如下指 [2]Patella D.Tramacere A.Smoothing scattered magnetotelluric 标.深度误差:在有井标定地区,误差≤5%;分层精 sounding curves.BOLL Geofis.1992.28(4):269 度:高阻地层≥1m;探测深度:20~4000m [3]Lamarque G.Improvement of MT data processing using station- ary and coherence tests.Geophys Prospect.1999.47(6):816 5结论 [4]Adam A,Szendroi J.Vero J.Different kinds of noises in magne- totelluric data processing Gerlands Beitraege zur Geophysik. (1)高精度电磁频谱技术突破了传统物探技术 1989,98(1):25 的思路,通过对电磁波地层反射信号的观测,经计算 [5]Chen L S,Wang G E.Chen J P.et al.A MT imaging tech 得到地下矿层电阻率曲线,从而获得地下岩性信息, nique.Acta Geophys Sin.1993,36(3):337 [6]Chouteal M,Bouchard K.Two dimensional terrain correction in 判断矿层深度、厚度, magnetotelluric surveys.Geophysics,1988.53(2):854 (2)在矿层厚度远小于探测深度时,可以将上 [7]徐世浙,王庆乙,王车,用边界单元法模拟二维地形对大地电 覆地层看作均匀大地状态,从而得到深度增加,上覆 磁的影响.地球物理学报,1992,35(3):380 地层电阻率也随之增加,探测深度与电磁波周期呈 [8]张大海,Szarka L,Adam A.三维大地电磁场相关测深曲线研 线性关系,通过三层断面的电阻率一测深曲线,可以 究.石油地球物理学报,2004,39(Sppl):4 [9]徐世浙,沅百尧,周辉,等。大地电磁场三维地形影响的数值 建立深度与电阻率值的对应关系,使得解译方便,从 模拟.中国科学D辑,1997,27(1):15 而求得矿层厚度和规模、 [10]Szarka L,Zhang D.Correlation between alternative magnetotel- (③)采集系统采用平板式电容传感器,与地下 luric response function and 3-D model parameter//EAGE 65th 目标层形成最佳耦合,从而克服了体积效应的弊端, ConferenceExhibition.Stavanger.2003:106 大大提高了探测精度 [11]王文祥,杨武洋.舜论与天然电磁波法物探.西安:陕西人民 出版社,2002:148 (4)该技术采用天然场源,不需要外加能源系 [12]王文祥,杨武洋.天然电磁波勘探研究的新进展.煤炭科学 统,具有环保的优势 技术,2005,33(1):18 (5)作为一项新技术,本方法在矿藏勘探方面 [13]郑杰青。浅析大地电磁频谱方法探测昆明地热的效果,云南 应用还比较少,经验也不足,解决的地质问题还不够 地质,1999,18(2):210 多,这需要在今后的实践中加以改进, [14]刘宝勤,安海静,屈健鹏.中国西北部分地区大地电磁测点 布设条件探讨.西北地震学报,2001,23(1):78 参考文献 [15]周仁安,桂宝林,王朝栋.高精度电磁频谱法在滇东煤层气 勘探中的应用.云南地质,2004,23(4):515 ]刘国栋,陈乐寿,大地电磁测深研究。北京:地震出版社, 1984,6 High precision method of electromagnetic frequency spectrum and its application in mineral exploration LI Zhong,WU Qiang),ZHOU Ren'an2),ZHA NG Lijuan) 1)ResoureesSafety Engineering School.China University of Mining and Technology,Beijing 100083.China 2)Dian-Qian-Gui Bureau of Oil Exploration,Kunming 650200.China ABSTRACI Based on the magnetotelluric (MT)theory,a technical law of high precision electromagnetic spectrum was illustrated.From comparative analysis of experiment,the exploring depth and the electromagnetic frequency could be regarded as a linear relation in local area,which made the stratum resistivity correspond to the exploring sounding curve.An observation system of underground coal seam resistivity using multi channel exploring method was designed.As a sensor,the paralleled capacitor overcame the disadvantage of volume effec- tiveness and improved the exploring precision.The system is adopted to explore coal seam and oil-gas.In com- parison with the practical drilling data,the accordance gives out a satisfied result with a figure of 80or more. KEY WORDS mineral exploration:electromagnetic spectrum:paralleled capacitor;multi-channel exploring method经过大量实测资料验证系统可以达到如下指 标.深度误差:在有井标定地区误差≤5%;分层精 度:高阻地层≥1m;探测深度:20~4000m; 5 结论 (1) 高精度电磁频谱技术突破了传统物探技术 的思路通过对电磁波地层反射信号的观测经计算 得到地下矿层电阻率曲线从而获得地下岩性信息 判断矿层深度、厚度. (2) 在矿层厚度远小于探测深度时可以将上 覆地层看作均匀大地状态从而得到深度增加上覆 地层电阻率也随之增加探测深度与电磁波周期呈 线性关系.通过三层断面的电阻率-测深曲线可以 建立深度与电阻率值的对应关系使得解译方便从 而求得矿层厚度和规模. (3) 采集系统采用平板式电容传感器与地下 目标层形成最佳耦合从而克服了体积效应的弊端 大大提高了探测精度. (4) 该技术采用天然场源不需要外加能源系 统具有环保的优势. (5) 作为一项新技术本方法在矿藏勘探方面 应用还比较少经验也不足解决的地质问题还不够 多这需要在今后的实践中加以改进. 参 考 文 献 [1] 刘国栋陈乐寿.大地电磁测深研究.北京:地震出版社 1984:6 [2] Patella DTramacere A.Smoothing scattered magnetotelluric sounding curves.BOLL Geofis199228(4):269 [3] Lamarque G.Improvement of MT data processing using stationary and coherence tests.Geophys Prospect199947(6):816 [4] Adam ASzendroi JVero J.Different kinds of noises in magnetotelluric data processing.Gerlands Beitraege zur Geophysik 198998(1):25 [5] Chen L SWang G EChen J Pet al.A MT imaging technique.Acta Geophys Sin199336(3):337 [6] Chouteal MBouchard K.Two-dimensional terrain correction in magnetotelluric surveys.Geophysics198853(2):854 [7] 徐世浙王庆乙王军.用边界单元法模拟二维地形对大地电 磁的影响.地球物理学报199235(3):380 [8] 张大海Szarka LAdam A.三维大地电磁场相关测深曲线研 究.石油地球物理学报200439(Suppl):4 [9] 徐世浙沅百尧周辉等.大地电磁场三维地形影响的数值 模拟.中国科学 D 辑199727(1):15 [10] Szarka LZhang D.Correlation between alternative magnetotelluric response function and3-D model parameter∥EAGE 65th Conference & Exhibition.Stavanger2003:106 [11] 王文祥杨武洋. 论与天然电磁波法勘探.西安:陕西人民 出版社2002:148 [12] 王文祥杨武洋.天然电磁波勘探研究的新进展.煤炭科学 技术200533(1):18 [13] 郑杰青.浅析大地电磁频谱方法探测昆明地热的效果.云南 地质199918(2):210 [14] 刘宝勤安海静屈健鹏.中国西北部分地区大地电磁测点 布设条件探讨.西北地震学报200123(1):78 [15] 周仁安桂宝林王朝栋.高精度电磁频谱法在滇东煤层气 勘探中的应用.云南地质200423(4):515 High-precision method of electromagnetic frequency spectrum and its application in mineral exploration LI Zhong 1)W U Qiang 1)ZHOU Ren’an 2)ZHA NG L ijuan 1) 1) Resources & Safety Engineering SchoolChina University of Mining and TechnologyBeijing100083China 2) Dian-Qian-Gui Bureau of Oil ExplorationKunming650200China ABSTRACT Based on the magnetotelluric (MT ) theorya technical law of high precision electromagnetic spectrum was illustrated.From comparative analysis of experimentthe exploring depth and the electromagnetic frequency could be regarded as a linear relation in local areawhich made the stratum resistivity correspond to the exploring sounding curve.An observation system of underground coal seam resistivity using mult-i channel exploring method was designed.As a sensorthe paralleled capacitor overcame the disadvantage of volume effectiveness and improved the exploring precision.The system is adopted to explore coal seam and oi-l gas.In comparison with the practical drilling datathe accordance gives out a satisfied result with a figure of80% or more. KEY WORDS mineral exploration;electromagnetic spectrum;paralleled capacitor;mult-i channel exploring method ·556· 北 京 科 技 大 学 学 报 第29卷