瞬变电磁法大定源回线全区视电阻率计算的研究
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摘要
瞬变电磁法(TEM)是一种被广泛应用的地球物理勘探方法,而大定源回线装置又是TEM法中比较常用的一种,在施工中有着其特定优点。但是因为接收线圈和发射线圈之间的相对位置不固定,使得其数据处理难度很大。目前能够处理大定源回线的数据的软件并不是很多,而且操作繁琐,效果并不理想。
本文利用1987年Raiche发布的大定源回线装置的响应公式,系统地分析大定源回线装置二次场响应的衰减特点,剖面曲线特点,其成果对于野外施工时参数的选择具有指导性的意义。
消除关断效应是TEM数据处理的重要步骤之一,为了消除关断时间的影响,本文采用的方法是直接使用斜阶跃波响应响应值来计算视电阻率。为了快速地得到准确的斜阶跃波的理论响应值,本文利用阶跃波的响应公式和杜哈美尔积分推导了斜阶跃波的响应公式,并给出了详细的推导步骤。
利用响应值计算视电阻率的过程是一个解隐函数的过程,在众多的算法中,本文选择了马奎特方法。考虑到使用全区响应值计算会出现多解的情况,本文采取将两个解全部求出,然后使用多种判别手段判别出合理解。为了实现这一设想,本文将马奎特法进行改进,使整个求解过程定能返回不同单调区间内的双解。在判别合理解的研究,中本文提出部分磁场判别法,并将此标准作为早期多解判别的主要别准,而晚期则使用了中心回线法作为主要判别标准,并以临近时间道的计算结果作为辅助判别标准。
为了增加实测数据的可用性,作者开发了原始数据的整理模块,模块中采用3点平滑的方法对其进行降噪处理。
最终开发出一套专门计算大定源回线数据的自编软件：瞬变电磁法大定源回线数据处理系统V1.0。通过设计用例的检验证明自编软件的算法有很强的适应性。最后在处理实测数据时取得了较为满意的效果。
Transient Electromagnetic Methods(TEM) is one kind of the widely used geophysical prospecting methods. And the Large Fixed Transmitting Loop is a commonly used in TEM. But because the position of the reciever ralative to the transmitting loop can be changed, to process this kind of data is more difficult than other kind of data. Now, there is only a few specialized software can process the data of Large Fixed Transmitting Loop. Operating these software is dificult, and the result is not satisfactory yet.
The oretical basis of this dissertation is the formula of the response of a large polygonal transmitting loop. With this formula that was which was published by Raiche in 1987, the characteristics of the response decay curves and the response section curve that is very important to indicate wild field sounding work, is systematically analyzed in this dissertation.
It is an important step to eliminate the influence of ramp turn-off. In order to get accurate apparent resistivity, an analytic formula of ramp turn-off response of a large polygonal fixed loop is derived in this dissertation through the formula of step turn-off response and Duhamel integral formula.
To get the apparent resistivity is a process of solution of an implicit function. In several common inversion algorithms, the Marquette inversion algorithm is choosen in this dissertation. The method to resolve the problem of multiple resolutions is to get all results of apparent resistivity first and then choose the reasonable result. In order to get all two apparent resistivity from one response value, the Marquette inversion algorithm is been modified to limit the search process in the monotone interval that contain the original value. The part of magnetic field is brought up in this dissertation as the main criterion to choose the reasonable result during early and intermediate stage, and the result calculated through central loop formula as the main criterion during later stage. Finally the auxiliary criterion is the near trace rensult.
To improve the availability of wild field data, the quaulity control module is developed in which the three point filter method is used.
Eventually a set of software, the large fixed transmitting Data Process System V1.0 is developed. The tests by self-designed test cases illustrate that the algorithms used in this software have very strong adaptability. A satisfactory result has been obtained in processing the measured data of HongQiling by this software.
本文利用1987年Raiche发布的大定源回线装置的响应公式,系统地分析大定源回线装置二次场响应的衰减特点,剖面曲线特点,其成果对于野外施工时参数的选择具有指导性的意义。
消除关断效应是TEM数据处理的重要步骤之一,为了消除关断时间的影响,本文采用的方法是直接使用斜阶跃波响应响应值来计算视电阻率。为了快速地得到准确的斜阶跃波的理论响应值,本文利用阶跃波的响应公式和杜哈美尔积分推导了斜阶跃波的响应公式,并给出了详细的推导步骤。
利用响应值计算视电阻率的过程是一个解隐函数的过程,在众多的算法中,本文选择了马奎特方法。考虑到使用全区响应值计算会出现多解的情况,本文采取将两个解全部求出,然后使用多种判别手段判别出合理解。为了实现这一设想,本文将马奎特法进行改进,使整个求解过程定能返回不同单调区间内的双解。在判别合理解的研究,中本文提出部分磁场判别法,并将此标准作为早期多解判别的主要别准,而晚期则使用了中心回线法作为主要判别标准,并以临近时间道的计算结果作为辅助判别标准。
为了增加实测数据的可用性,作者开发了原始数据的整理模块,模块中采用3点平滑的方法对其进行降噪处理。
最终开发出一套专门计算大定源回线数据的自编软件：瞬变电磁法大定源回线数据处理系统V1.0。通过设计用例的检验证明自编软件的算法有很强的适应性。最后在处理实测数据时取得了较为满意的效果。
Transient Electromagnetic Methods(TEM) is one kind of the widely used geophysical prospecting methods. And the Large Fixed Transmitting Loop is a commonly used in TEM. But because the position of the reciever ralative to the transmitting loop can be changed, to process this kind of data is more difficult than other kind of data. Now, there is only a few specialized software can process the data of Large Fixed Transmitting Loop. Operating these software is dificult, and the result is not satisfactory yet.
The oretical basis of this dissertation is the formula of the response of a large polygonal transmitting loop. With this formula that was which was published by Raiche in 1987, the characteristics of the response decay curves and the response section curve that is very important to indicate wild field sounding work, is systematically analyzed in this dissertation.
It is an important step to eliminate the influence of ramp turn-off. In order to get accurate apparent resistivity, an analytic formula of ramp turn-off response of a large polygonal fixed loop is derived in this dissertation through the formula of step turn-off response and Duhamel integral formula.
To get the apparent resistivity is a process of solution of an implicit function. In several common inversion algorithms, the Marquette inversion algorithm is choosen in this dissertation. The method to resolve the problem of multiple resolutions is to get all results of apparent resistivity first and then choose the reasonable result. In order to get all two apparent resistivity from one response value, the Marquette inversion algorithm is been modified to limit the search process in the monotone interval that contain the original value. The part of magnetic field is brought up in this dissertation as the main criterion to choose the reasonable result during early and intermediate stage, and the result calculated through central loop formula as the main criterion during later stage. Finally the auxiliary criterion is the near trace rensult.
To improve the availability of wild field data, the quaulity control module is developed in which the three point filter method is used.
Eventually a set of software, the large fixed transmitting Data Process System V1.0 is developed. The tests by self-designed test cases illustrate that the algorithms used in this software have very strong adaptability. A satisfactory result has been obtained in processing the measured data of HongQiling by this software.
引文
[1]牛之琏.时间域电磁法原理[M].长沙：中南大学出版社.2007
[2]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
[3]Raiche A.P.. Trainsient electromagnetic field computations for polygonal loops on layered earth[J]. Geophysics,1987, V52:785-793
[4]Raiche A.P., Coggon J.H.. Analytic Green's tensors for Integral equationmodellinp[J]. Geophys,1975, V42:1035-1038
[5]Raiche, A.P., Gallagher, R.G... Apparent resistivity and diffusion velocity[J]. Geophysics,1985, V50:1628-1633
[6]Asten M W, Prince D G. Transient EM sounding by the in/out-loop method [J]. Exploration Geophysics,1985,16:165
[7]Eaton P A, Hohman GW. An evalution of electromagnetic methods in the presence of geolgic noise[J]. Geophysics,1987,52(8)
[8]Fitterman D.V., Anderson W.L.. Effect of transmitter turn off time ontransient sounding[J]. Geoexploration,24,131-146
[9]Misac.N.Nabighian.. Time Domain Electromagnetic Prospecting Methods[J]. Electromagnetic Methods inApplied Geophysics,1994,2(6):427-458.
[10]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[11]杨生.TEM中心回线法考滤关断时间的全期视电阻率计算方法[J].物探与化探,2008(6)
[12]许建荣,李爱勇,杨生.TEM中心回线法瞬变磁场求取和全区视电阻率计算[J].地质与勘探,2008(6)
[13]李文尧.瞬变电磁法观测电位影响因素研究[硕士学位论文].昆明：昆明理工大学,2005
[14]杨云见、王绪本、何展翔.瞬变电磁法中的斜阶跃波效应及常规的几种校正方法分析[J].物探化探计算技术,2008(2)
[15]张成范、翁爱华、孙世栋等.计算矩形大定源回线瞬变电磁测深全区视电阻率[J].吉林大学学报(地球科学版),2009(4)
[16]李建慧、刘树才、李富等.大定源瞬变电磁法矩形发射回线激发的电磁场[J].物探化探计算技术,2008(2)
[17]侯朝勇、陈卫、李勇等.时间域电磁法大定回线源装置异常响应的分析处理.中国地球物理学会第22届年会论文集,2006
[18]孙天财.发射电流波形对瞬变电磁测量结果影响及校正的研究[硕士学位论文].重庆：重庆大学,2008
[19]白登海.瞬变电磁法中两种关断电流对响应函数的影响及其应对策略[J].地震地质,2001,23(2)：245
[20]代英玲.基于偶极和大定源装置的瞬变电磁数据处理方法研究[硕士学位论文].长春：吉林大学,2008
[21]Raiche A.P.. The effect of ramp function turn-off on the TEM response oflayered earth[J]. Exploration.Geophys,15:37-41
[22]Raiche A.P, Spies B.R.. Coincident loop transient electromagnetic master curves for interpretation of two-layer earths [J]. Geophysics,1981,46(1):53-64
[23]Spies B.R, Raiche A.P.. Calculation of apparent conductivity for the Transient
electromagnetic(coincident loop)method using an HP-67 calculator[J]. Geophysics,45: 1197-1204
[24]McNeill J.D, Edwards R.N, Thorborn M.. Approximate calculation of thetransient electromagnetic response from buried conductive half-space[J]. Geophysics,1984,49(7)
[25]冯思臣,王绪本,阮帅.一维大地电磁测深几种反演算法的比较研究[J].石油地球物理勘探,2004,39(5)：594-59
[26]戚志鹏,李貅.大定源装置下瞬变电磁场垂直和水平分量的视电阻率定义.中国地球物理第25届年会论文集,2009
[27]石显新,闫述,傅君眉等.瞬变电磁法中心回线装置资料解释方法的改进[J].地球物理学报,2009,52(7)：1931-1936
[28]孙天财,付志红,谢品芳.斜阶跃场源关断时间对测量结果的影响及校正研究[J].工程地球物理学报,2008,5(3)
[29]李建平,李桐林,赵雪峰等.层状介质任意形状回线源瞬变电磁全区视电阻率的研究[J].地球物理学进展,2007,V22(6)
[30]Spies B.R and Dwight E.Eggers.. The use and misuse of apparent resistivityin electromagnetic methods[J]. Geophysics,1986,51(7):1462-1471
[31]Macnae J and Lamontagne Y.. Discussion on "Comparison of apparentresistivity functions for transient electromagnetic methods " by A.P.Raiche[J]. Geophysics,1984, 49,312-313.
[32]Ravenhurst W.R.. Microcomputer modeling of fixed-loop time-domain Emsystems, Canada Crone Geophysics Limited Technical Note,1987
[33]Nabighian M.N.. Quasi-static transient response of conducing half-space[J]. Geophysics,1979,48,107-109
[34]Lee T., Lewis R.. Tansiant response of a large loop on a layered ground. Geophys.Prosp.,1974, V22,430-444
[35]陈卫,杨生,王有霖等.时间域瞬变电磁法在地质勘查中的应用[J].矿产与地质,2006
[36]廖忠,李文尧.瞬变电磁法在腾冲热水塘寻找地热的应用效果[J].工程勘察,2002
[37]李文尧,拔家祥.瞬变电磁法在抗洪抢险中的应用[J].云南大学学报(自然科学版),2000(S1)
[38]唐新功,胡文宝,严良俊等.瞬变电磁法油藏动态监测模拟[J].石油物探,2004(3)
[39]周平,施俊法.瞬变电磁法(TEM)新进展及其在寻找深部隐伏矿中的应用[J].地质与勘探,2007(6)
[40]周小平,陈卫,阮百尧等.瞬变电磁法在安徽某区寻找隐伏矿的应用[J].中国地球物理学会第22届年会论文集,2006
[41]汤金云,于景郝,王扬州等.矿井瞬变电磁人文噪声干扰及处理技术研究[J].2008(2)
[42]杨生.大地电磁测深法环境噪声抑制研究及其应用[博士学位论文].长沙：中南大学,2004
[43]蒋邦远.深部找矿与蒋氏TEM双定源回线装置方案[J].物探化探计算技术,2007(S1)
[44]杨长福,林长佑,陈军营等.三维瞬变电磁法反演[J].地震学报,2000,
22(4)：377-384
[45]陈明生,闫述等.二维地质体的瞬变电磁场响应特征[J].地震地质,2001,
23(2)：252-256
[2]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
[3]Raiche A.P.. Trainsient electromagnetic field computations for polygonal loops on layered earth[J]. Geophysics,1987, V52:785-793
[4]Raiche A.P., Coggon J.H.. Analytic Green's tensors for Integral equationmodellinp[J]. Geophys,1975, V42:1035-1038
[5]Raiche, A.P., Gallagher, R.G... Apparent resistivity and diffusion velocity[J]. Geophysics,1985, V50:1628-1633
[6]Asten M W, Prince D G. Transient EM sounding by the in/out-loop method [J]. Exploration Geophysics,1985,16:165
[7]Eaton P A, Hohman GW. An evalution of electromagnetic methods in the presence of geolgic noise[J]. Geophysics,1987,52(8)
[8]Fitterman D.V., Anderson W.L.. Effect of transmitter turn off time ontransient sounding[J]. Geoexploration,24,131-146
[9]Misac.N.Nabighian.. Time Domain Electromagnetic Prospecting Methods[J]. Electromagnetic Methods inApplied Geophysics,1994,2(6):427-458.
[10]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[11]杨生.TEM中心回线法考滤关断时间的全期视电阻率计算方法[J].物探与化探,2008(6)
[12]许建荣,李爱勇,杨生.TEM中心回线法瞬变磁场求取和全区视电阻率计算[J].地质与勘探,2008(6)
[13]李文尧.瞬变电磁法观测电位影响因素研究[硕士学位论文].昆明：昆明理工大学,2005
[14]杨云见、王绪本、何展翔.瞬变电磁法中的斜阶跃波效应及常规的几种校正方法分析[J].物探化探计算技术,2008(2)
[15]张成范、翁爱华、孙世栋等.计算矩形大定源回线瞬变电磁测深全区视电阻率[J].吉林大学学报(地球科学版),2009(4)
[16]李建慧、刘树才、李富等.大定源瞬变电磁法矩形发射回线激发的电磁场[J].物探化探计算技术,2008(2)
[17]侯朝勇、陈卫、李勇等.时间域电磁法大定回线源装置异常响应的分析处理.中国地球物理学会第22届年会论文集,2006
[18]孙天财.发射电流波形对瞬变电磁测量结果影响及校正的研究[硕士学位论文].重庆：重庆大学,2008
[19]白登海.瞬变电磁法中两种关断电流对响应函数的影响及其应对策略[J].地震地质,2001,23(2)：245
[20]代英玲.基于偶极和大定源装置的瞬变电磁数据处理方法研究[硕士学位论文].长春：吉林大学,2008
[21]Raiche A.P.. The effect of ramp function turn-off on the TEM response oflayered earth[J]. Exploration.Geophys,15:37-41
[22]Raiche A.P, Spies B.R.. Coincident loop transient electromagnetic master curves for interpretation of two-layer earths [J]. Geophysics,1981,46(1):53-64
[23]Spies B.R, Raiche A.P.. Calculation of apparent conductivity for the Transient
electromagnetic(coincident loop)method using an HP-67 calculator[J]. Geophysics,45: 1197-1204
[24]McNeill J.D, Edwards R.N, Thorborn M.. Approximate calculation of thetransient electromagnetic response from buried conductive half-space[J]. Geophysics,1984,49(7)
[25]冯思臣,王绪本,阮帅.一维大地电磁测深几种反演算法的比较研究[J].石油地球物理勘探,2004,39(5)：594-59
[26]戚志鹏,李貅.大定源装置下瞬变电磁场垂直和水平分量的视电阻率定义.中国地球物理第25届年会论文集,2009
[27]石显新,闫述,傅君眉等.瞬变电磁法中心回线装置资料解释方法的改进[J].地球物理学报,2009,52(7)：1931-1936
[28]孙天财,付志红,谢品芳.斜阶跃场源关断时间对测量结果的影响及校正研究[J].工程地球物理学报,2008,5(3)
[29]李建平,李桐林,赵雪峰等.层状介质任意形状回线源瞬变电磁全区视电阻率的研究[J].地球物理学进展,2007,V22(6)
[30]Spies B.R and Dwight E.Eggers.. The use and misuse of apparent resistivityin electromagnetic methods[J]. Geophysics,1986,51(7):1462-1471
[31]Macnae J and Lamontagne Y.. Discussion on "Comparison of apparentresistivity functions for transient electromagnetic methods " by A.P.Raiche[J]. Geophysics,1984, 49,312-313.
[32]Ravenhurst W.R.. Microcomputer modeling of fixed-loop time-domain Emsystems, Canada Crone Geophysics Limited Technical Note,1987
[33]Nabighian M.N.. Quasi-static transient response of conducing half-space[J]. Geophysics,1979,48,107-109
[34]Lee T., Lewis R.. Tansiant response of a large loop on a layered ground. Geophys.Prosp.,1974, V22,430-444
[35]陈卫,杨生,王有霖等.时间域瞬变电磁法在地质勘查中的应用[J].矿产与地质,2006
[36]廖忠,李文尧.瞬变电磁法在腾冲热水塘寻找地热的应用效果[J].工程勘察,2002
[37]李文尧,拔家祥.瞬变电磁法在抗洪抢险中的应用[J].云南大学学报(自然科学版),2000(S1)
[38]唐新功,胡文宝,严良俊等.瞬变电磁法油藏动态监测模拟[J].石油物探,2004(3)
[39]周平,施俊法.瞬变电磁法(TEM)新进展及其在寻找深部隐伏矿中的应用[J].地质与勘探,2007(6)
[40]周小平,陈卫,阮百尧等.瞬变电磁法在安徽某区寻找隐伏矿的应用[J].中国地球物理学会第22届年会论文集,2006
[41]汤金云,于景郝,王扬州等.矿井瞬变电磁人文噪声干扰及处理技术研究[J].2008(2)
[42]杨生.大地电磁测深法环境噪声抑制研究及其应用[博士学位论文].长沙：中南大学,2004
[43]蒋邦远.深部找矿与蒋氏TEM双定源回线装置方案[J].物探化探计算技术,2007(S1)
[44]杨长福,林长佑,陈军营等.三维瞬变电磁法反演[J].地震学报,2000,
22(4)：377-384
[45]陈明生,闫述等.二维地质体的瞬变电磁场响应特征[J].地震地质,2001,
23(2)：252-256