【摘要】：地球物理電磁法勘探領(lǐng)域發(fā)展至今,從最初的直接定性解釋,已經(jīng)發(fā)展到可以較為精確的定量分析。這其中,正反演技術(shù)的飛速發(fā)展為這種變化起到了巨大的作用。首先正演技術(shù),從上世紀(jì)的積分方程法,逐步發(fā)展到三維有限差分法,此外自適應(yīng)有限元的應(yīng)用,也開(kāi)始顯現(xiàn)出模擬復(fù)雜地形的巨大優(yōu)勢(shì)。而在反演技術(shù)上,盡管存在陷入局部極小的問(wèn)題,但大量的實(shí)踐證明當(dāng)前的反演技術(shù)在一定程度上能較好的完成勘探需要。在實(shí)際應(yīng)用中,還有許多因素嚴(yán)重影響電磁法勘探的觀測(cè)數(shù)據(jù),首先是強(qiáng)烈的起伏地形,其次就是可能存在嚴(yán)重的各向異性。除了這兩個(gè)問(wèn)題外,在部分區(qū)域還存在磁導(dǎo)率、極化率等參數(shù)的強(qiáng)烈影響。當(dāng)前電磁法勘探正在逐一研究這些問(wèn)題,期望能做到更加精確可靠的解釋。本文的研究重點(diǎn)就是在可控源音頻大地電磁法(Controlled Source Audio-Frequency Magnetotelluric Methods) 里,引入電阻率各向異性參數(shù)。嚴(yán)格意義的各向異性參數(shù)是任意各向異性,即任意方向都是不同的。盡管這種方式更符合實(shí)際情況,但在目前的反演領(lǐng)域里,是無(wú)法反演的。因此在本文的研究中將各向異性簡(jiǎn)化為主軸各向異性,在一定程度上雖然降低了可靠性,但也同時(shí)為反演極大的降低了多解性。從這個(gè)角度上來(lái)說(shuō),也是在目前理論體系下,做到了相對(duì)最優(yōu)化。確立了這個(gè)研究思路后,本文選用三維交錯(cuò)網(wǎng)格有限差分作為正演算子,該方法容易實(shí)現(xiàn),且運(yùn)算效率高,是目前地球物理內(nèi)廣泛應(yīng)用的正演技術(shù)。在實(shí)現(xiàn)了 CSAMT三維主軸各向異性正演后,進(jìn)行了正演分析的研究,結(jié)果表明采用張量源作為發(fā)射源,其多分量數(shù)據(jù)能盡可能的識(shí)別各向異性參數(shù)。進(jìn)一步的,本文選用了有限內(nèi)存擬牛頓法(LBFGS)與非線性共軛梯度法(NLCG)作為反演研究手段,首先完成了張量CSAMT三維各向同性反演研究。研究結(jié)果表明,不考慮場(chǎng)源效應(yīng)而直接用大地電磁進(jìn)行反演,深部反演結(jié)果不可信,同時(shí)張量CSAMT的反演結(jié)果分辨率也明顯高于標(biāo)量CSAMT,此外本文同時(shí)還進(jìn)行了 LBFGS與NLCG的反演效果與效率的對(duì)比研究。最后,本文的各向異性反演理論試算還證明,忽略各向異性直接進(jìn)行各向同性反演,會(huì)給最終的反演帶來(lái)很多假異常,嚴(yán)重影響最終的解釋。
[Abstract]:The rapid development of forward and inversion techniques has played an important role in this change. First of all, forward modeling techniques, from the integral equation method in the last century, have gradually developed to the three-dimensional finite difference method. The application of adaptive finite element method has also begun to show great advantages in simulating complex terrain. In inversion technology, although there is a problem of falling into local minima, a large number of practices have proved that the current inversion technology can better fulfill exploration needs to a certain extent. In practical application, there are still many factors seriously affecting electromagnetic prospecting. In addition to these two problems, there are also strong effects of permeability and polarizability in some areas. Currently, electromagnetic exploration is studying these problems one by one, hoping to achieve more accurate and reliable interpretation. The emphasis is on introducing resistivity anisotropy parameters into the Controlled Source Audio-Frequency Magnetotelluric Method. Strictly speaking, the anisotropy parameters are arbitrary anisotropy, i.e. all directions are different. In this paper, the anisotropy is simplified as the principal axis anisotropy, which reduces the reliability to a certain extent, but also greatly reduces the multiplicity of solutions for the inversion. In this paper, three-dimensional staggered grid finite difference method is chosen as forward operator. This method is easy to implement and has high computing efficiency. It is a widely used forward technique in geophysics at present. Furthermore, the finite-memory quasi-Newton method (LBFGS) and the nonlinear conjugate gradient method (NLCG) are selected as the inversion methods. First, the three-dimensional isotropic inversion of tensor CSAMT is completed. The results show that the magnetotelluric inversion is carried out directly without considering the field source effect, and the deep inversion is carried out. The inversion results of tensor CSAMT are not credible, and the resolution of tensor CSAMT is obviously higher than that of scalar CSAMT. In addition, the inversion effects and efficiency of LBFGS and NLCG are compared. Finally, the theoretical calculation of anisotropic inversion in this paper also proves that the inversion results will be the final inversion band if the anisotropy is ignored. There are many false anomalies which seriously affect the final interpretation.
【學(xué)位授予單位】：中國(guó)地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：P631.325

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 謝茂筆;譚捍東;王X鵬;郭長(zhǎng)安;張志勇;李志強(qiáng);;可控源音頻大地電磁法三維張量阻抗響應(yīng)特征研究[J];地球物理學(xué)進(jìn)展;2017年02期

2 趙寧;王緒本;秦策;阮帥;;三維頻率域可控源電磁反演研究[J];地球物理學(xué)報(bào);2016年01期

3 殷長(zhǎng)春;賁放;劉云鶴;黃威;蔡晶;;三維任意各向異性介質(zhì)中海洋可控源電磁法正演研究[J];地球物理學(xué)報(bào);2014年12期

4 董浩;魏文博;葉高峰;金勝;景建恩;;基于有限差分正演的帶地形三維大地電磁反演方法[J];地球物理學(xué)報(bào);2014年03期

5 胡祥云;霍光譜;高銳;王海燕;黃一凡;張?jiān)葡?左博新;蔡建超;;大地電磁各向異性二維模擬及實(shí)例分析[J];地球物理學(xué)報(bào);2013年12期

6 劉云鶴;殷長(zhǎng)春;;三維頻率域航空電磁反演研究[J];地球物理學(xué)報(bào);2013年12期

7 張昆;董浩;嚴(yán)加永;呂慶田;魏文博;何鈺嫻;;一種并行的大地電磁場(chǎng)非線性共軛梯度三維反演方法[J];地球物理學(xué)報(bào);2013年11期

8 胡祥云;李焱;楊文采;魏文博;高銳;韓波;彭榮華;;大地電磁三維數(shù)據(jù)空間反演并行算法研究[J];地球物理學(xué)報(bào);2012年12期

9 李焱;胡祥云;楊文采;魏文博;方慧;韓波;彭榮華;;大地電磁三維交錯(cuò)網(wǎng)格有限差分?jǐn)?shù)值模擬的并行計(jì)算研究[J];地球物理學(xué)報(bào);2012年12期

10 林昌洪;譚捍東;舒晴;佟拓;譚嘉言;;可控源音頻大地電磁三維共軛梯度反演研究[J];地球物理學(xué)報(bào);2012年11期

相關(guān)博士學(xué)位論文 前1條

1 阮帥;三維大地電磁有限內(nèi)存擬牛頓反演[D];成都理工大學(xué);2015年

，

本文編號(hào)：2240135