【摘要】：視磁化強度反演,是利用在觀測面采集的實際磁力數(shù)據(jù)來反推地下異常體的磁性參數(shù)以及空間賦存狀態(tài)的一種地球物理手段,它是地球物理勘探的重要手段之一,由于反演得到的磁化強度是相對值,而非地下異常體的磁化強度真實值,因此稱之為“視”磁化強度反演。這種方法的基本思想就是對地下待反演地質(zhì)體進行網(wǎng)格剖分,通過不停的反演迭代直至達到精度要求,來計算出所有剖分網(wǎng)格單元的視磁化強度。這種計算方法的主要問題就是反演多解性嚴重:第一、觀測磁異常是地下的空間體積效應;第二、采集的數(shù)據(jù)是離散的而不是連續(xù)的。因此,如何降低反演多解性的影響,提高反演成像的精度,一直以來都是視磁化強度反演問題中的重中之重。針對磁反演的多解性問題,本文提出了基于正則化下延方法的視磁化強度全空間反演。其核心思想是通過對觀測面磁異常場進行正則化向下延拓,得到不同深度的磁場分布,通過結(jié)合觀測場和下延場的異常數(shù)據(jù),來增大反演原始數(shù)據(jù)量;此外,當場源埋深較大時,在地表觀測到的異常信號較弱,而通過正則化下延所得到的下延磁異常場,可以在深度上更接近異常體賦存位置,有利于突出異常信號。該方法的關鍵是保證觀測磁異常場的正則化下延精度,重點是反演目標函數(shù)的構(gòu)建。理論模型試驗結(jié)果表明,利用本文提出的方法所進行的視磁化強度反演,其反演精度要明顯高于僅用觀測場數(shù)據(jù)進行反演而得到的結(jié)果。尤其在存在多個不等深場源體情況下,其反演得到的異常體位置較傳統(tǒng)方法相比更接近異常體的真實賦存位置,這說明該方法在縱向分辨能力上有顯著提高。對北三臺地區(qū)實際資料進行了處理,反演得到研究區(qū)的視磁化強度三維空間分布,并對火成巖進行圈定,結(jié)果與實際鉆井資料基本吻合,進一步驗證了方法的實用性。
[Abstract]:The inversion of apparent magnetization is a geophysical method which uses the actual magnetic data collected on the observational plane to push back the magnetic parameters and the spatial occurrence state of the underground anomalous body. It is one of the important means of geophysical exploration. Because the magnetization obtained by inversion is a relative value, but not the true value of the magnetization of an underground anomaly, it is called "apparent" magnetization inversion. The basic idea of this method is to mesh the geological bodies to be retrieved, and to calculate the apparent magnetization of all the meshes by continuous inversion iteration until the precision is reached. The main problem of this method is that the inversion multi-solution is serious: first, the observed magnetic anomaly is the volume effect of underground space; second, the collected data is discrete rather than continuous. Therefore, how to reduce the influence of inversion multi-solution and improve the accuracy of inversion imaging has always been the most important problem in the inversion of apparent magnetization. Aiming at the multi-solution problem of magnetic inversion, this paper presents a full-space inversion of apparent magnetization based on regularized downscaling method. The core idea is to obtain the magnetic field distribution of different depths by regularizing the anomalous magnetic field of the observation surface, and to increase the original data by combining the anomaly data of the observation field and the downgoing field. In addition, the anomalous signals observed on the surface of the earth are weaker when the depth of the source is larger on the spot, and the anomalous magnetic field obtained by regularizing the downward continuation can be closer to the location of the anomalous body in depth, which is advantageous to outburst the abnormal signal. The key point of this method is to ensure the regularization and downscaling accuracy of the observed magnetic anomaly field, with emphasis on the construction of the inversion objective function. The experimental results of theoretical model show that the inversion accuracy of apparent magnetization inversion based on the method proposed in this paper is obviously higher than that obtained by only using the observational field data. Especially in the case of multiple source bodies with unequal depth, the position of anomalous bodies obtained by inversion is closer to the real location of anomalous bodies than that of traditional methods, which indicates that the vertical resolution of this method is improved significantly. The actual data of Beisantai area are processed and the 3-D spatial distribution of apparent magnetization is obtained by inversion. The igneous rocks are delineated. The results are in good agreement with the actual drilling data, which further verifies the practicability of the method.
【學位授予單位】：中國石油大學(華東)
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P631

【參考文獻】

相關期刊論文 前10條

1 雷文敏;吳健生;;南海東北部陸緣基底磁異常反演與解釋[J];同濟大學學報(自然科學版);2012年11期

2 于會臻;劉展;;基于結(jié)構(gòu)模型的磁性基底反演[J];物探化探計算技術;2012年03期

3 陳召曦;孟小紅;郭良輝;;重磁數(shù)據(jù)三維物性反演方法進展[J];地球物理學進展;2012年02期

4 劉展;于會臻;陳挺;;雙重約束下的密度三維反演[J];中國石油大學學報(自然科學版);2011年06期

5 趙希剛;吳漢寧;柏冠軍;王靖華;;重磁異常解釋斷裂構(gòu)造的處理方法及圖示技術[J];地球物理學進展;2008年02期

6 徐世浙;余海龍;姚敬金;曹洛華;;新疆色爾特能地區(qū)視密度和視磁性的反演[J];物探化探計算技術;2007年S1期

7 姚長利;鄭元滿;張聿文;;重磁異常三維物性反演隨機子域法方法技術[J];地球物理學報;2007年05期

8 徐世浙;曹洛華;姚敬金;;重力異常三維反演——視密度成像方法技術的應用[J];物探與化探;2007年01期

9 劉展;班麗;魏巍;王萬銀;郭加樹;;濟陽坳陷花溝地區(qū)火成巖重磁成像解釋方法[J];中國石油大學學報(自然科學版);2007年01期

10 徐世浙;;位場延拓的積分-迭代法[J];地球物理學報;2006年04期

相關博士學位論文 前1條

1 班麗;相關約束重磁三維定量反演方法研究[D];中國石油大學;2009年

相關碩士學位論文 前3條

1 李中芹;基于深度變化的磁場正則化下延方法研究[D];中國石油大學;2011年

2 王純;基于深度變化的重力位場正則化下延方法研究[D];中國石油大學;2010年

3 戴偉;磁異常處理與信息提取技術研究[D];成都理工大學;2008年

，

本文編號：2370414