本文選題：核磁共振 + 陣列線圈��； 參考：《吉林大學(xué)》2015年碩士論文

【摘要】：地面核磁共振測(cè)深技術(shù)憑借對(duì)地下水直接探測(cè)和定量評(píng)估的優(yōu)勢(shì)成為一種快速興起的現(xiàn)代地球物理找水方法，近年來(lái)在探索開(kāi)采地下淡水資源和預(yù)防水災(zāi)害方面得到廣泛應(yīng)用。但是，針對(duì)地質(zhì)構(gòu)造復(fù)雜、地下水非層狀不均勻分布的二維核磁共振探測(cè)方法仍不成熟，存在發(fā)射/接收分離線圈多次測(cè)量綜合成像耗時(shí)過(guò)長(zhǎng)、工作效率低和二維初始振幅反演信號(hào)數(shù)據(jù)利用率低、只能得到含水反演結(jié)果的問(wèn)題。為了解決這些問(wèn)題，本文開(kāi)展了陣列式測(cè)量模式的分辨率和成像效果研究；提出了利用全部的矩核磁共振探測(cè)包絡(luò)信號(hào)進(jìn)行反演的二維QT反演方法（Q-Time Inversion，簡(jiǎn)稱QT），，這種反演方法能夠有效利用所有激發(fā)脈沖和探測(cè)時(shí)間得到的核磁共振信號(hào)，完成弛豫時(shí)間和含水量雙參數(shù)的核磁共振成像；最后利用陣列式測(cè)量模式進(jìn)行數(shù)值仿真和對(duì)實(shí)測(cè)核磁共振數(shù)據(jù)進(jìn)行數(shù)據(jù)處理，對(duì)比分析二維初始振幅反演方法、二維單指數(shù)QT反演方法和二維多指數(shù)QT反演方法的核磁共振成像結(jié)果。 針對(duì)二維核磁共振探測(cè)時(shí)接收和發(fā)射線圈沿測(cè)線移動(dòng)多次測(cè)量效率低的問(wèn)題，根據(jù)陣列式測(cè)量理論，本文提出了三組不同的線圈類型和線圈尺寸的鋪設(shè)方案，構(gòu)造了一個(gè)具有多個(gè)含水體的復(fù)雜含水模型，分別計(jì)算和分析三組線圈的的分辨率和成像效果，結(jié)果表明陣列式測(cè)量模式能夠提高工作效率，不同的線圈尺寸和測(cè)量模式具有不同的優(yōu)勢(shì)，根據(jù)實(shí)際需要采用不同的測(cè)量方案。 針對(duì)二維初始振幅反演利用擬合得到的初始振幅進(jìn)行數(shù)據(jù)解釋，未考慮弛豫時(shí)間等信息的問(wèn)題，基于核磁共振信號(hào)的指數(shù)特性和全部的包絡(luò)數(shù)據(jù)，提出并推導(dǎo)了針對(duì)單個(gè)弛豫時(shí)間的二維單指數(shù)QT反演方法和針對(duì)多個(gè)弛豫時(shí)間的二維多指數(shù)QT反演方法，通過(guò)矩陣轉(zhuǎn)換成一般形式并給出求解方法。二維QT反演（二維單指數(shù)QT反演和二維多指數(shù)QT反演）實(shí)現(xiàn)了含水量和弛豫時(shí)間雙參數(shù)成像，能夠更加準(zhǔn)確地反應(yīng)地下水賦存信息。通過(guò)構(gòu)造數(shù)值模型，分別利用二維初始振幅反演、二維單指數(shù)QT反演和二維多指數(shù)QT反演進(jìn)行數(shù)據(jù)解釋，對(duì)比分析三種反演方法的成像結(jié)果。 最后，利用德國(guó)北部的Eddelstorf地區(qū)陣列式測(cè)量核磁共振數(shù)據(jù)，分別采用二維初始振幅反演、二維單指數(shù)QT反演和二維多指數(shù)QT反演方法進(jìn)行數(shù)據(jù)處理，與地質(zhì)資料進(jìn)行對(duì)比，驗(yàn)證二維單指數(shù)QT反演方法和二維多指數(shù)QT反演方法的有效性。 采用陣列式測(cè)量模式和二維QT反演方法能夠?qū)崿F(xiàn)縮短探測(cè)時(shí)間、提高測(cè)量效率和對(duì)具有多種弛豫時(shí)間的復(fù)雜含水構(gòu)造的弛豫時(shí)間和含水量雙參數(shù)成像，并通過(guò)實(shí)例驗(yàn)證了測(cè)量方式和反演方法的優(yōu)越性和實(shí)用性，對(duì)二維核磁共振探測(cè)技術(shù)的應(yīng)用具有指導(dǎo)意義。
[Abstract]:Based on the advantages of direct detection and quantitative assessment of groundwater, surface nuclear magnetic resonance sounding (NMR) technology has become a rapidly emerging modern geophysical method for water prospecting. In recent years, it has been widely used in the exploration of underground freshwater resources and the prevention of water disasters.However, in view of the complexity of geological structure and the uneven distribution of groundwater, the 2D NMR detection method is still immature, and it takes a long time for multiple measurements and integrated imaging of transmitting / receiving separation coils.The problem of low efficiency and low utilization ratio of 2-D initial amplitude inversion signal can only obtain the result of water-bearing inversion.In order to solve these problems, the resolution and imaging effect of array measurement mode are studied in this paper.A two-dimensional QT inversion method called Q-Time inversion (QT) is presented, which uses all the moment nuclear magnetic resonance detection envelope signals for inversion. This inversion method can effectively utilize the nuclear magnetic resonance signals obtained from all the excitation pulses and the detection time.Nuclear magnetic resonance imaging with two parameters of relaxation time and water content is completed. Finally, numerical simulation and data processing of measured nuclear magnetic resonance data are carried out using array measurement mode, and the two-dimensional initial amplitude inversion method is compared and analyzed.Magnetic resonance imaging results of two dimensional single exponent QT inversion and two dimensional multi exponential QT inversion.In order to solve the problem of low measurement efficiency of receiving and transmitting coils moving along the measuring line in two-dimensional nuclear magnetic resonance detection, according to the theory of array measurement, three different types of coils and laying schemes of coil size are proposed in this paper.A complex water-bearing model with multiple water bodies is constructed. The resolution and imaging effect of three sets of coils are calculated and analyzed respectively. The results show that the array measurement mode can improve the working efficiency.Different coil sizes and measuring modes have different advantages, and different measurement schemes are adopted according to the actual needs.Based on the exponential characteristic of nuclear magnetic resonance signal and the whole envelope data, the initial amplitude is interpreted by fitting the original amplitude, and the relaxation time is not taken into account.Two dimensional single exponent QT inversion method for single relaxation time and two dimensional multi exponential QT inversion method for multiple relaxation time are proposed and derived.Two-dimensional QT inversion (two-dimensional single-exponent QT inversion and two-dimensional multi-exponential QT inversion) realizes two-parameter imaging of water content and relaxation time, which can reflect groundwater occurrence information more accurately.By constructing a numerical model, the imaging results of the three inversion methods are compared and analyzed by using two-dimensional initial amplitude inversion, two-dimensional single-exponential QT inversion and two-dimensional multi-exponential QT inversion.Finally, the nuclear magnetic resonance data are measured by array method in Eddelstorf area in northern Germany. The data are processed by two-dimensional initial amplitude inversion, two-dimensional single-index QT inversion and two-dimensional multi-index QT inversion, respectively, and compared with geological data.The validity of two dimensional single index QT inversion method and two dimensional multi exponential QT inversion method is verified.The array measurement mode and two-dimensional QT inversion method can be used to shorten the detection time, improve the measurement efficiency and image the relaxation time and water content of complex water-bearing structures with multiple relaxation times.The advantages and practicability of the measurement method and inversion method are verified by an example, which is of guiding significance to the application of two-dimensional nuclear magnetic resonance detection technology.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TH763.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前9條

1 張文權(quán);翁愛(ài)華;;地面核磁共振正則化反演方法研究[J];吉林大學(xué)學(xué)報(bào)(地球科學(xué)版);2007年04期

2 林君;;核磁共振找水技術(shù)的研究現(xiàn)狀與發(fā)展趨勢(shì)[J];地球物理學(xué)進(jìn)展;2010年02期

3 翁愛(ài)華;王雪秋;劉國(guó)興;莫修文;王德利;;導(dǎo)電性影響的地面核磁共振反演[J];地球物理學(xué)報(bào);2007年03期

4 戴苗;胡祥云;吳海波;蔣龍聰;楊迪琨;;地面核磁共振找水反演[J];地球物理學(xué)報(bào);2009年10期

5 蔣川東;林君;段清明;田寶鳳;郝薈萃;;二維陣列線圈核磁共振地下水探測(cè)理論研究[J];地球物理學(xué)報(bào);2011年11期

6 邵雁;;核磁共振技術(shù)應(yīng)用于煤礦中查找老窯及巖溶水害的探討[J];礦業(yè)安全與環(huán)保;2008年01期

7 林君;蔣川東;段清明;王應(yīng)吉;秦勝伍;林婷婷;;復(fù)雜條件下地下水磁共振探測(cè)與災(zāi)害水源探查研究進(jìn)展[J];吉林大學(xué)學(xué)報(bào)(地球科學(xué)版);2012年05期

8 林婷婷;蔣川東;齊鑫;史文龍;段清明;林君;;地面磁共振測(cè)深分布式探測(cè)方法與關(guān)鍵技術(shù)[J];地球物理學(xué)報(bào);2013年11期

9 ;Instructions for Authors[J];Applied Geophysics;2008年01期

相關(guān)博士學(xué)位論文 前1條

1 蔣川東;核磁共振2D/3D地下水成像方法及其陣列式地面探測(cè)系統(tǒng)研究[D];吉林大學(xué);2013年

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