分离线圈地面核磁共振找水正演  

Forward of surface nuclear magnetic resonance with separated loops

作　　者：龚胜平[1] 李振宇[2] 周欣[3,4] 陈亮[1] 

机构地区：[1]中国地质科学院地球物理地球化学勘查研究所,廊坊065000 [2]中国地质大学(武汉)地球物理与空间信息学院,武汉430074 [3]中国地震局地震研究所,武汉430071 [4]武汉地震工程研究院,武汉430071

出　　处：《地球物理学进展》2011年第2期739-745,共7页Progress in Geophysics

基　　金：中国地质科学院地球物理地球化学勘查研究所基本科研业务费专项资金资助

摘　　要：分离线圈地面核磁共振找水方法是将激发线圈与接收线圈分离开来的找水探测方法.文中阐释分离线圈地面核磁共振找水方法正演表达式;利用高斯积分方法计算了分离线圈正演公式中的核函数.通过分析核函数的变化规律,得出分离线圈地面核磁共振方法具有较高的横向分辨率.通过计算全空间的核函数矩阵,将地下含水模型离散化,实现分离线圈地面核磁共振找水3D模型正演快速计算.通过对比计算1D含水模型响应,本文的计算选取网格的越小,正演精度越高.文中计算装置对模型的响应,分析正演曲线随着模型的埋深与装置的不同呈现的变化规律,研究分离线圈地面核磁共振的分辨特性及探测特点.The main advantage of the Surface NMR method, compared with other geophysical method for water prospecting is that the surface measurement of the nuclear magnetic resonance（NMR） signal from water molecules in the subsurface ensures that it only responds to the subsurface water. With separated transmitter and receiver loops is a new method for Surface nuclear magnetic resonance. This paper illustrates forward equations of surface NMR method with separated loops for water investigation. The Gaussian integral method is being played in the formula calculation of the Kernel function. By analyzing the characteristics of Kernel function, this method has a higher lateral resolution. By calculating the kernel function matrix of the whole space, discrete the model of underground water, accumulating the response of each unit, we achieve rapidly 3D forward modelling calculations of SNMR with separated loops method. By comparing the response of 1D model calculated in this article, it shows that the smaller the grid we selected, the higher accuracy produced. Computing the response of the model using difference devices, analyzing the forward result with difference depth of the water aquifer and the device variation, we study the distinguish features and characteristics of the detection using surface nuclear magnetic resonance with separated loops.

关 键 词：分离线圈 地面核磁共振 正演 三维 

分 类 号：P631[天文地球—地质矿产勘探]