物探与化探
物探與化探
물탐여화탐
GEOPHYSICAL AND GEOCHEMICAL EXPLORATION
2015年
1期
118-124
,共7页
仇根根%张小博%裴发根%袁永真%白大为%张鹏辉
仇根根%張小博%裴髮根%袁永真%白大為%張鵬輝
구근근%장소박%배발근%원영진%백대위%장붕휘
大地电磁法%一维反演%二维反演%三维反演%层状介质%数值模拟
大地電磁法%一維反縯%二維反縯%三維反縯%層狀介質%數值模擬
대지전자법%일유반연%이유반연%삼유반연%층상개질%수치모의
magnetotelluric survey%1D inversion%2D inversion%3D inversion%layered media%Numerical simulation
设计了一个简单的三维模型:三维低阻异常体和高阻异常体位于一维层状介质模型中,以“十”字型和“米”字型观测剖面方式作为模拟方式,开展模型一维、二维、三维反演技术有效性对比试验,其中一维反演计算采用自适应正则化( ARIA)反演,二维反演计算采用非线性共轭梯度( NLCG)反演,三维反演计算采用REBOCC三维反演,将剖面下方不同的反演结果与原始模型进行对比分析,发现:在该模型条件下,一维和二维反演都能得到反映模型真实信息的结果,REBOCC三维反演更偏向重建原始模型的宏观电性特征;在一维反演结果中,对于深部的电性结构特征,通常TE极化模式的反演结果好于TM极化模式,TE/TM几何平均值反演结果介于前两者之间;在二维反演结果中,通常TM极化模式的反演结果好于TE极化模式,TE/TM联合模式反演结果与TM极化模型相当,甚至更好;模型REBOCC三维反演相比一维、二维反演更易受反演结果多解性影响,REBOCC三维反演结果偏向重建原始模型的宏观电性特征。
設計瞭一箇簡單的三維模型:三維低阻異常體和高阻異常體位于一維層狀介質模型中,以“十”字型和“米”字型觀測剖麵方式作為模擬方式,開展模型一維、二維、三維反縯技術有效性對比試驗,其中一維反縯計算採用自適應正則化( ARIA)反縯,二維反縯計算採用非線性共軛梯度( NLCG)反縯,三維反縯計算採用REBOCC三維反縯,將剖麵下方不同的反縯結果與原始模型進行對比分析,髮現:在該模型條件下,一維和二維反縯都能得到反映模型真實信息的結果,REBOCC三維反縯更偏嚮重建原始模型的宏觀電性特徵;在一維反縯結果中,對于深部的電性結構特徵,通常TE極化模式的反縯結果好于TM極化模式,TE/TM幾何平均值反縯結果介于前兩者之間;在二維反縯結果中,通常TM極化模式的反縯結果好于TE極化模式,TE/TM聯閤模式反縯結果與TM極化模型相噹,甚至更好;模型REBOCC三維反縯相比一維、二維反縯更易受反縯結果多解性影響,REBOCC三維反縯結果偏嚮重建原始模型的宏觀電性特徵。
설계료일개간단적삼유모형:삼유저조이상체화고조이상체위우일유층상개질모형중,이“십”자형화“미”자형관측부면방식작위모의방식,개전모형일유、이유、삼유반연기술유효성대비시험,기중일유반연계산채용자괄응정칙화( ARIA)반연,이유반연계산채용비선성공액제도( NLCG)반연,삼유반연계산채용REBOCC삼유반연,장부면하방불동적반연결과여원시모형진행대비분석,발현:재해모형조건하,일유화이유반연도능득도반영모형진실신식적결과,REBOCC삼유반연경편향중건원시모형적굉관전성특정;재일유반연결과중,대우심부적전성결구특정,통상TE겁화모식적반연결과호우TM겁화모식,TE/TM궤하평균치반연결과개우전량자지간;재이유반연결과중,통상TM겁화모식적반연결과호우TE겁화모식,TE/TM연합모식반연결과여TM겁화모형상당,심지경호;모형REBOCC삼유반연상비일유、이유반연경역수반연결과다해성영향,REBOCC삼유반연결과편향중건원시모형적굉관전성특정。
A simple three?dimensional model, a low?resistivity abnormal body and a high resistance abnormal body located in one?di?mensional layered medium were designed in this paper. The authors used the"+" and"?" type observation profiles as the analog form to carry out the comparative experimental study of the effectiveness of MT 1D, 2D, 3D inversion. The authors employed adaptive regu?larization ( ARIA) to perform 1D inversion, and adopted nonlinear conjugate gradient ( NLCG) to conduct 2D inversion and REBOCC to carry out 3D inversion. The comparison of the different inversion results below the profile with the original model shows that 1D and 2D inversion can be reflected in the results of real model information, while 3D inversion of REBOCC tends to build a three?dimension?al model of macroscopic electrical characteristics. In the 1D inversion results, as for the deep electrical structure, the inversion result shows that the TE polarization mode is better than TM polarization mode, and the combination mode of TE and TM has a medium result between the TE and TM. In the 2D inversion results, usually the TM polarization mode is better than TE polarization mode, and the in?version results of combination mode of TE with TM are almost equal with the TM polarization mode inversion results, or even better. In the 3D REBOCC inversion results, due to the influence of multiple solutions on inversion results, the 3D inversion of REBOCC tends to build a three?dimensional model of macroscopic electrical characteristics.