用户名: 密码: 验证码:
CSAMT中的IP效应影响及应用研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
在可控源音频大地电磁法(CSAMT)的正、反演计算中都把大地的电阻率看作一个与频率无关的实数,但由于IP效应的影响,大地电阻率实际上是一个随频率而变化的复数,在电磁场的响应中实际上包含了IP响应的成份。对基本Cole-Cole模型的频谱分析发现,复电阻率的实部一般远大于虚部,实部与幅值、虚部与相位变化规律一致;极化率和频率相关系数变化对模型电阻率幅值的影响要大于时间常数变化造成的影响,在提取IP参数时可以根据经验取为常数;复Cole-Cole模型的频谱变化规律与基本模型的规律基本一致,同类参数都发生变化对幅值的影响取决于总的变化量,而相位主要受参数小的基本模型的制约。IP效应对Ex、卡尼亚视电阻率的影响远大于对Hy的影响,这种影响主要发生在中低频段,在高频段IP效应基本消失,在分析IP效应和提取IP参数时要在中低频段进行,同时还要排除近场效应的影响;极化模型参数的变化对电磁场分量的影响规律与对自身频谱曲线的影响规律相似;IP效应对卡尼亚视电阻率幅值的影响大于对相位的影响,各参数的影响水平也不相同,极化率参数和频率相关系数的影响大,时间常数的影响小,在提取IP参数时,要优先考虑影响大的参数。建立了基于最小二乘方提取IP参数的目标函数,设计了算法程序,为加快函数的收敛速度,采用梯度法改变模型参数;利用给定的模型作为实测数据,对提取算法进行了测试。针对卡尼亚视电阻率中存在的IP效应的来源,提出了在CSAMT原始资料中去除IP效应的方法,它利用视电阻率替换的方法实现IP效应的去除;利用这种方法对在长白山地区寻找地热资源的资料进行了处理,反演结果能够合理地解释地热资源的形成原因。
Controlled source audio-frequency magnetotelluric(CSAMT) whics is developed on the basis of magnetotelluric method and the audiofrequency magnetotelluric method is an active source electromagnetic exploation method. In recent years it's theory research is continuous increasing, in the field of exploating concealed ore, oil, gas, geothermal resources and Hydrology has made good geological effect.
     Induced polarization effect (IP) is caused by the effect of polarization in interface between the electronic conductor and the aqueous solution electrodes or the film polarization between clay surface and solution. IP phenomenon could be observed by DC or AC induced electronic field established artificially in mineralization rocks primarily consists of electronic conductor, graphitization rocks and ion conductor rocks. Because of the IP effect, the earth resistivity is a plural changing with frequency, but in the CSAMT the earth resistivity is regarded as a real number parametre in both forward and inversion, which is unrelated to frequency, ignoring the IP ingredients of electromagnetic response. These are a variety of plural models to describe polarization effect, this paper briefly summaries them.
     In order to analysis the influence to electromagnetic field (Ex, Hy) produced by IP, firstly We derivate the calculation formula of the electromagnetic field in the homogeneous medium and layered medium, use the discrete method to calculate Ex and Hy in layered medium. To avoid attenuation of Hy in high frequency, we use a high precision filter coefficient to calculate it. According to scalar measurement of CSAMT, we summary it's working condition and parameters of observation so as to analysis the influence of IP.
     We analysis the spectrum characteristics of basic Cole-Cole model, and find that the complex resistivity's real part generally far more than that of imaginary part, variation law between real part and amplitude or between imaginary part and phase follow the same variation law when Cole-Cole model parametres change. Real part is always positive and become smaller with the parameters of polarizability increasing, it tend to be a steady value at high frequeny band. Imaginary part changes according to concave curve, the high and low frequency band tend to be zero, and in the middle frequency band it gets negative value. The general varying trend's of real part and imaginary part when frequency correlation coefficient changes is similar to that of when polarization parametre changes. Real part increases in low frequency band with frequency correlation coefficient increasing, the absolute value of the imaginary part in lower and higher frequency band increases with the decrease of the C. Real part decrease with the increasing ofτ. But difference among real parts is very not obvious whenτis big enough, imaginary part changes as to concave curvee whenτis small, but it increases monotonously with frequency increase whenτis big enough, and finally it close to zero. And at higher frequency band, the absolute value of imaginary part decreased with the increasing ofτ, at low frequency band it changes more complexly. Then studies the influence level when model parameters changes, and find that the changing of polarization parametre and frequency correlation coefficient can produce greatly influences on amplitude and phase, but the time parameter changing has a little influence, so in extracting IP parameters can take it as an experience constant. By analysising the spectrum characteristics of compound Cole-Cole model, we find each parameters on the influence law of compound model is consistent with the influence law of basic model, if two models'similar parameters both change, the influence on amplitude depends on the total variation, and phase is mainly affected by the basic model with small parameters.
     The paper analyzes the IP effect in homogeneous half-space and various types of cross-section layer earth by using the model of Cole-Cole, find that the influence to Ex and to Cagniard resistivity is far more than to Hy, this kind of influence mainly takes place in low-middle frequency band, at high frequencies IP effect disappeares off basically, so to analyzes the IP effect of CSAMT mainly considers the low-middle frequency band. Also, there exists the effect of near field at low frequency band, this is must be excluded. The influence law to electromagnetic field components is similar with the influence law of their own spectrum curve when the model parameters changing. The analysis showes that IP influence has a greatly effection on resistivity amplitude than that on phase, the influence level of various parameters is not the same:polarizability parameters and frequency correlation coefficient have greater influence than that caused by the time constant, to extract IP parameters should priority consider the parametres which can produce great influence.
     Give the method of how to established polarization model of CSAMT measurement on polarization level layer, establish target function of least squares sense to extract the IP parameters. And the objective function and parameter expression is optimized. We give detailes of calculation, and in order to accelerate the convergence speed, using gradient method to modify model parameters. Run the procedures by setting initial model portfolio and using given model as the experimental data to extraction algorithm as to verify its validity.
     According to the source of IP effect existing in the Cagniard resistivity, puts forward mean to remove IP effect from original data. This method firstly use the original data to design layered polarization model and establish objective function to extract IP parameters, then use extracted parameters to calculate model apparent resistivity of relevant frequency, and use it to replace the apparent resistivity of the original data with corresponding frequency, so to update the original CSAMT data. We apply this treatment to the CSAMT data of Changbai mountain area exploring for geothermal resources, the inversion result can reasonably explain the reasons for the formation of the geothermal resources.
     The main innovation of this paper is:
     (1) Through the study of Cole-Cole model's spectrum, we find that the influence level on the amplitude and phase of complex resistivity by the polarizability parameter and the correlation coefficent of frequency when they are changing is larger than the influence level by parameter of time, at the same time we find that it is more superior to extract IP parameters through real part or amplitude than imaginary part. Through the study of compound Cole-Cole model's spectrum when its parametre is changes, we find that the compound model can be equal to a basic Cole-Cole model. In addition, we prove the amplitude of complex resistivity is lower than that of zero-frequency, it provides a thereunder for choosing initial parameter when doing inversion.
     (2) Through the analyzing the result of cagniard apparent resistivity caused by the parameters changing of Cole-Cole model, concluding that the influence caused by the polarizability parameter or the frequency correlation coefficient is larger than that caused by time constant. This provides an evidence for regarding it as an empirical value when extracting IP parameters.
     (3) We design an object function based on least squares sense to extract IP parameters, which modifing model parameters by gradient direction in order to speed up the convergence of the objective function.
     (4) For the source of the IP effect consisting in cagniard apparent resistivity, we propose a method that can remove IP effect in the original data of CSAMT. The core of this method is to use IP parameters extracted, to calculate the theoretical value of relative frequency of apparent resistivity, and replace the value of corresponding frequency of original data, at the same time providing approach to select initial model and relative parameter.
     This paper's endeavor will further promote the research of IP effect in the fields of Controlled Source Audio-frequency Magnetotelluric(CSATM), Magnetotelluric method(MT) and Transient electromagnetic method(TEM), and has an important theoretical and realistic significance on how to remove the IP effect, use IP effect in these fields.
引文
[1]Cagniard L. Basic theory of the magnetotelluric method of geophysical prospecting. Geophysics,1953,18(1):605~635.
    [2]Vozoff K. Magnetotelluric Methods.USA:Geophysics Reprint Series, 1986.1~763.
    [3]王家映.大地电磁拟地震解释法[M].北京:石油工业出版社,1955.1-172.
    [4]石应骏等,大地电磁测深教程[M].北京:地震出版社,1985.
    [5]王家映.石油电法勘探[M].北京:石油工业出版社。1993.
    [6]何继善.可控音频大地电磁法[M].长沙:中南工业大学出版社,1990.1-169.
    [7]石昆法.可控音频大地电磁法理论与应用[M].北京:科学出版社,1999.1-85
    [8]Goldstein M A, Strangway DW. Audio-frequence magnetotellurics with a grounded electric dipole source. Geophysics,1975,40(1):669~683.
    [9]Zonge K. L., Hughes L.J. Controlled source audio-frequency magnetotellurics. In:Electromagnetic Methods in Applied Geophysics. 1991,2(B):713~809
    [10]李金铭.地电场与电法勘探[M].北京:地质出版社[M],2005.7 126
    [11]刘国兴.电法勘探原理与方法[M].北京:地质出版社[M],2005.195-97
    [12]傅良魁.激发极化法[M].北京:地质出版社,1982.6
    [13]何继善.双频激电法[M].北京:高等教育出版社,2006.
    [14]王妙月等.勘探地球物理学[M].北京:地震出版社,2003.
    [15]傅良魁.频谱激电法若干理论研究[J].物探与化探,1985.9:38-42.
    [16]李金铭.激发极化方法技术指南[M].北京:地质出版社,2004.
    [17]陈绍求,陈明伟.激发极化法在石英脉型金矿探测中的应用[J].矿产与地质,1999,13(72):245-248.
    [18]黄仙珊.激发极化法在桃坪山铅锌矿区的应用效果[J].福建地质,2002,16(2):114-116.
    [19]雒志锋.激发极化法在寻找斑岩型铜矿中的应用[J].地质找矿论丛,2003,18(增):149-151.
    [20]舒明.激发极化法在砚山阿空锰矿区的应用[J].云南地质,2004,23(3):385-389.
    [21]陈蜀雁,刘永明.双频激电法在阿勒泰山区快速找矿评价中的应用[J]中南大学学报(自然科学版),2006,,37(3):588-592.
    [22]柳建新,刘春明,佟铁钢等.双频激电法在西藏某铜多金属矿带的应用[J].地质与勘探,2004,40(2):59-61.
    [23]徐笑民.双频激电法的找矿效果[J].中国有色金属学报,1993,3(4):84-87.
    [24]J.伯廷,J.洛布.激发极化法的实验和理论[M].北京:地质出版社,1980.12.
    [25]李天成,牛滨华,孙春岩,赵丽.2D电阻率正反演成像在水平和垂直模型上的异常响应研究[J].地球物理学进展,2007,22(3):940-946.
    [26]王光杰,王勇,李帝铨等.基于遗传算法CSAMT反演计算研究[J].地球物理学进展,2006,21(4):1285-1289.
    [27]王若,王妙月,底青云等.CSAMT方法在隧道勘察中的应用[J].石油地球物理勘探,2004,39(B11):43-45、56.
    [28]Lu X,李汝传.张量CSAMT数据的二维反演[J].物探化探译丛,1998,4:29-33.
    [29]Muralietc S. Comparasion of anomalous effects de-fermined using telluric field sand time domain IP[J]. Technique (Test Results) Bult. Aust. Soc. Expior.Geophys,1982,2(1/2):44~45.
    [30]Gasperikova E, Morrison H F. Mapping of induced polarization using Natural fields[J].Geophysics,2001,66(1):137~147.
    [31]Marali S. Comparison of anomalous effects determined using telluric fields and time domain IP technique (test results). Bult. Aust. Soc. Explor [J]. Geophys,1982,2 (1/2):44~45.
    [32]Morrison H F, Gasperikova E. Mapping of induced polarization using natural fields [J].Expanded Abstracts of 66th Annual Internat SEG Mtg, 1996,603-606.
    [33]Gsperikova E. Mapping of induced polarization using natural fields [D]. Berkeley:University of california at Berkeley,1999.
    [34]Erika G, Frank M H. Apping of induced polarization using natural fields [J].Geophysics,2001,66(1):137~147.
    [35]吴汉荣,王式铭.利用天然电磁场进行激发极化法测量的可能性[J].物探与化探,1978(1):62-64.
    [36]杨进,谭捍东,傅良魁.被动源激发极化法的野外试验结果[J].现代地 质,1998,12(3):436-441.
    [37]杨进,谭捍东,傅良魁.被动源激发极化法的数值模拟结果[J].现代、地质,1999,13(增刊):112-113.
    [38]陈清礼.天然场源激电法基础理论研究[D].北京:中国地质大学(北京).2001
    [39]李金铭,陈清礼,杨冠鼎.极化水平层上天然场源激电测深的理论研究[J].物探与化探,2003,27(4):280-283.
    [40]罗延钟,张胜业,熊彬.天然场源激电法的可行性[J].地球物理学报,2003,46(1):125-130.
    [41]陈清礼,胡文宝,李金铭.由MT资料反演真谱参数的基本原理[J].石油天然气学报(江汉石油学院学报),2006,28(6):61-64.
    [42]曹中林,何展翔,昌彦君.MT激电效应的模拟研究及在油气检测中的应用[J].地球物理学进展,2006,21(4):1252-1257.
    [43]岳安平,底青云,石昆法.从CSAMT信号中提取IP信息探讨[J].地球物理学进展,2007.12,22(6):1925-1930.
    [44]刘磊,昌彦君,曹中林.可极化大地上CSAMT激发极化效应的研究[J].工程地球物理学报,2008.12,5(6):p686-690.
    [45]汤井田,黄磊,余灿林,席玉萍CSAMT法中极化层的视电阻率响应[J].工程地球物理学报,2008.12,5(6):p648-651.
    [46]黄磊CSAMT中的IP效应提取[D].中南大学.2009
    [47]考夫曼A.A.,凯勒G.V.频率域和时间域电磁测深[M].北京:地质 出版社,1987,48-92.
    [48]Sandberg S K, Hohmann G W. Controlled source audio-frequency magnetotellurics in geothermal exploration [J]. Geophysics,1982, 47(1):100~116.
    [49]Batrel L C, Jacobson R D. Results of a controlled source audiofrequency magnetotelluric survey at the Puhimau thermal area.Kilauea Volcano, Hawaii [J]. Geophysics,1987,52:665~677.
    [50]Wannamaker P. Tensor CSAMT survey over the SulphurSprings thermal area.Valles Caldera, New Mexico, U.S.A., Part 1:implications for structure of the western caldera [J]. Geophysics,1997,62(2):451~465.
    [51]汤井田,何继善.可控源音频大地电磁法及其应用[M].长沙:中南大学出版社,2005.
    [52]H.K. Johansen. Fast Hankel transform. Geophysical Prospecting[J], Vol.27:877~901.
    [53]王延良,刘洪.快速汉克尔变换滤波系数解析计算法[C].1987年全国电测深学术研讨会论文.
    [54]朴化荣,殷长春.频率测深正演问题滤波算法及人机联作反演[J].物化探计算技术,1987.6,Vol.9,No.2.p137-148
    [55]F.N. Kong. Hankel transform filters for dipole antenna radiationin a conductive medium.Geophysical Prospecting[J],2007,55, p83-89.
    [56]程志平.电法勘探教程[M].北京:冶金工业出版社,2007.5
    [57]赵国泽,陈小斌,汤吉.中国地球电磁法新进展和发展趋势[J].地球物理学进展,2007,22(4):1171-1180.
    [58]底青云,王光杰,安志国等.南水北调西线千米深长隧洞围岩构造地 球物理勘探[J].地球物理学报,2006,49(6):1836-1842.
    [59]底青云,Martyn Unsworth,王妙月.复杂介质有限元法2.5维可控源音频大地电磁法数值模拟[J].地球物理学报,2004,47(4):723-730.
    [60]底青云,王妙月,石昆法.高分辨率V6系统在矿山顶板涌水隐患中的应用研究[J].航空学报,2002,45(5):744-754.
    [61]底青云,伍法权.地球物理综合勘探技术在南水北调西线工程深埋长隧洞勘察中的应用[J].岩石力学与工程学报,2005,24(20):3631-3638.
    [62]龚飞,底青云,王光杰等CSAMT方法对虎跳峡龙蟠右岸变形体的反应特征[J].工程地质学报,2005,13(4):542-545.
    [63]底青云,王若等.可控源音频大地电磁数据正反演及方法应用.北京:科学出版社,2008.4。
    [64]童茂松,丁柱.岩石复电阻率频谱模型参数的反演[J].测井技术,2006,30(4):303-305.
    [65]丁柱,童茂松,潘涛.岩石复电阻率Dias模型及其参数求取方法[J].物探化探计算技术,2005,27(2):135-137.
    [66]丁柱,童茂松,潘涛.岩石复电阻率Dias模型及其反演方法[J].大庆石油地质与开发,2005,24(5):90-92.
    [67]张塞珍.岩(矿)石频谱激电特征与结构构造和导电矿物成份[M].北京:中国科学技术出版社.1994.
    [68]Wait.J.R. Overvoltage research and geophysical applications[M]: Pergamen Press,London,1959.
    [69]Ward S.H., Fraser D.C. Conduction of electricity in rocks.in soc. Expel. Geophys. Ed.Comm. Mining Geophys,1967,197~223.
    [70]Madden T.R., Cantwell T. Induced polarization:A review, in soc.Expel. Geophys.Ed.Comm. Mining Geophys,1967,373~400.
    [71]Dias C.A. A non-grounded method for measuring electrical induced polarization and conductivity. Ph.D thesis,1968,Univ.California Berkeley.
    [72]Dias C.A. Analytical model for a polarizable medium at radio and lower frequency[J], Geophysics.1972,77,4945~4956.
    [73]Dias C.A, Developments in a model to describe low-frequency electrical polarization of rocks[J], Geophysics,2000,65:437~451.
    [74]Zonge K.L.,et al,Comparison of time,frequency and phase measurements in IP[J]. Geophysics Prospecting,1972,20:626~648.
    [75]Cole K S,Cole R H.Dispersion and absorption in dielectrics[J]. Chemical physic,1941,9:341~351
    [76]Pelton,W.H.,Interpretation of complex resistivity and dielectric data,Ph.D thesis,1977, Univ. Utah.
    [77]Pelton W H, Ward S H, Hallof P G,etal. Mineral discrimination and removal of inductive coupling with multifrequency IP [J]. Geophysics, 1978.VOL.43, NO.3:588~609.
    [78]Anderson M.O., Keller G. V., A study in induced polarization. Geophysics,1964,29(3):848~864.
    [79]Zonge, K.L. et al. Comparision of time, frequency and phase measurements in IP. Geophysical Prospecting,1972, VOL.20:626~648.
    [80]Fraser D.A., et al. Conductivity spectra of racks from the craigmont ore environent. Geophysics,1964,29(6):832~847.
    [81]Seigel H O.Mathematical formulation and type curves for induced polarization[J]. Geophysics,1959,24:547~565.
    [82]Angron Y. Induced polarization.:A preliminary study of its chemical basis. Geophysics,1977,42(3):788~803.
    [83]Agunloye. Induced polarization.:Simulation and inversion of nonlinear mineral electrodes[J]. Pure and Applied Geophysics.1983.121 (1):63~69.
    [84]Basokur A T, Rasmussen T M, Kaya C, et al. Comparison of induced-polarization and controlled source audio-magnctotellurics methods for massive chalcopyrite exploration in a volcanic area [J]. Geophysics,1997,62(6):1087-1096.
    [85]Boerner D E, Wright J A, Thurlow J G &Reed L E. Tensor CSAMT studies at the Buchans Mine in central Newfound land[J]. Geophysics, 1993,58(1):12-19.
    [86]CHEN C S. Application of CSAMT method for gold-copper deposits in Chinkuashih Area. Northern Taiwan [J]. TAO,1993,4(4):339-350.
    [87]阮百尧,罗润林.一种新的复电阻率频谱参数的递推反演方法[J].物探化探计算技术,2003,25(4):298-301.
    [88]张辉,李桐林.利用Cole-Cole模型组合得到SIP真参数的联合频谱最优化反演[J].西北地震学报,2004,35(4):662-666.
    [89]蔡军涛,阮百尧,罗润林.层状大地视真频参数测深曲线的反演[J].中南大学学报(自然科学版),2000,21(2):155-158.
    [90]万鹏.频谱激电法中Cole-Cole模型频谱特性分析[J].内蒙古石油化工,2006,5:69-71.
    [91]罗延钟,吴之训.谱激电法中频率相关系数的应用[J].地球物理学报,1992,35(4):490-500.
    [92]刘小军,苏朱刘,胡文宝.用遗传算法提取频谱激电法谱参数[J].江汉石油学院学报,2004,26(2):74-75.
    [93]王家映.地球物理反演理论[M].北京:高等教育出版社.2002.9
    [94]Siripunvaporn W. and Egbert G. An efficient data subspace inversion method for 2-D MT:Geophysics,2000,65:791~803.
    [95]Pederson L.B. and Gharibi. Automatic 1-D inversion of MT data:finding the simplest possible mode that fit the data. Geophysics,2000,65:773~782.
    [96]刘国栋等译.大地电磁测深法[M].北京:地质出版社.1987.8
    [97]王若,王妙月.一维全资料CSAMT反演[J].石油地球物理勘探,2007,42(1):108~114.1977, Univ.Utah.
    [98]王若,王妙月.可控源音频大地电磁数据的反演方法[J].地球物理学进展,2003,18(6):197-202.
    [99]朱添宝,施婉华等.解析雅可比矩阵的一维CSAMT反演[J].地球物理学报,2005,18(1):39-45
    [100]王妙月,底青云等.利用CSAMT资料同时重构1-D介电常数导磁率和电阻率三个电性参数的像[C].理论与应用地球物理进展.气象出版社,2002:216-224.
    [101]汤井田,周聪,邓晓红.CSAMT视电阻率曲线对水平层状大地的识别与分辨.地质与勘探,2010,16(11):1079-1085.
    [102]安之国,底青云CSAMT法对低阻薄层结构分辨能力的探讨[J].地震地磁观测与研究,2006,27(4):32-37
    [103]王艳,林君等.CSAMT法深部低阻分辨能力及方法研究[J].中国矿业大学学报,2009,38(1):86-90.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700