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  本文選題：重磁勘探 + 三維�。� 參考：《成都理工大學(xué)》2015年碩士論文

【摘要】：重磁物性模型構(gòu)建中,因為不涉及場源復(fù)雜的形態(tài)變化,并且更容易結(jié)合地質(zhì)等先驗信息和約束條件,因此物性反演已成為重磁反演發(fā)展的趨勢。而反演技術(shù)的關(guān)鍵是充分利用約束條件盡量避免多解性。所以,本文深入研究了重磁三維約束反演,對比了不同模型下約束反演的理論效果,并通過處理實際資料驗證了約束反演良好效果。首先,在研究了重磁異�；纠碚摰幕A(chǔ)上,重點研究了重磁異常點源法計算方法,得到了點源法的重磁異常正演離散公式,并編制Fortran程序?qū)崿F(xiàn)了模型的重磁異常正演計算。其次,在熟悉反演基本理論的基礎(chǔ)上重點研究了英屬哥倫比亞大學(xué)的Li和Oldenburg提出了重磁三維光滑約束反演。構(gòu)建的目標(biāo)函數(shù)既包含了數(shù)據(jù)擬合函數(shù),又包含了模型函數(shù),其中的正則化因子,用來控制模型函數(shù)在目標(biāo)函數(shù)中的權(quán)重。并將深度加權(quán)函數(shù)引入到目標(biāo)函數(shù)中,克服了核函數(shù)的自然衰減(即趨膚效應(yīng))。推導(dǎo)了粗糙度函數(shù),并將其引入到模型函數(shù)中,實現(xiàn)了模型的光滑約束。采用比廣義逆法更好的共軛梯度法求解目標(biāo)函數(shù)的最小化。再次,本文以磁異常反演為例,分別設(shè)計了一個直立長方體模型、兩個長方體模型、五個長方體模型及傾斜板狀體模型,運用了深度加權(quán)約束、模型加權(quán)約束進行反演,并對比分析了有無深度加權(quán)、有無模型加權(quán)時的反演效果,并得出有約束時恢復(fù)的模型更接近真實模型。最后,將約束反演方法用于西藏東巧地區(qū)的重磁勘探,取得了較好的效果,驗證了方法的有效性。
[Abstract]:In the construction of gravity and magnetic physical properties model, physical inversion has become the trend of gravity and magnetic inversion because it does not involve complex morphological changes of field sources, and it is easier to combine prior information and constraints such as geology. The key of inversion technique is to make full use of constraints to avoid multi-solution. Therefore, in this paper, the gravity and magnetic three-dimensional constrained inversion is deeply studied, and the theoretical results of constrained inversion under different models are compared, and the good results of constrained inversion are verified by processing the actual data. Firstly, on the basis of studying the basic theory of gravity and magnetic anomaly, the calculation method of gravity and magnetic anomaly point source method is studied emphatically, and the forward discrete formula of gravity and magnetic anomaly is obtained, and the Fortran program is compiled to realize the forward calculation of gravity and magnetic anomaly. Secondly, on the basis of the basic theory of inversion, Li and Oldenburg of the University of British Columbia proposed the gravity and magnetic 3D smooth constrained inversion. The constructed objective function includes both the data fitting function and the model function. The regularization factor is used to control the weight of the model function in the objective function. The depth-weighted function is introduced into the objective function to overcome the natural attenuation of the kernel function (i.e. skin effect). The roughness function is derived and introduced into the model function to realize the smooth constraint of the model. The conjugate gradient method, which is better than the generalized inverse method, is used to minimize the objective function. Thirdly, taking the inversion of magnetic anomalies as an example, this paper designs a vertical cuboid model, two cuboid models, five cuboid models and inclined slab model respectively. The inversion results with or without depth weighting and model weighting are compared and analyzed, and it is concluded that the model with constraints is closer to the real model. Finally, the constrained inversion method is applied to gravity and magnetic exploration in Dongqiao area, Tibet, and good results are obtained, and the validity of the method is verified.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P631

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本文編號：2022311