基于形态小波的核磁共振测井信号去噪及现场应用研究  

De-noising of NMR Logging Signals Based on the Morphological Wavelet and its Real Application

作　　者：蔡剑华[1] 黎小琴[1] 张勋[1] 

机构地区：[1]湖南文理学院信息研究所，湖南常德415000

出　　处：《地质与勘探》2016年第1期146-151,共6页Geology and Exploration

基　　金：国家自然科学基金项目(41304098);湖南省自然科学基金项目(12JJ4034);湖南省教育厅青年项目(13B076);湖南省重点建设学科-光学基金;湖南文理学院博士启动项目;湖南省重点实验室“光电信息集成与光学制造技术”;“湖南省光电信息技术校企联合人才培养基地”共同资助

摘　　要：核磁共振测井中采集到的回波串信号十分微弱,而背景噪声很强,使信噪分离困难。为解决这一问题,引入了结合数学形态学的特征识别和小波分解的多分辨率分析特性的形态小波方法。讨论了方法的数据基础和应用步骤,并与小波软阈值方法处理结果进行了对比分析。实测数据处理结果表明:形态小波去噪方法具有良好的细节保留和抗噪声能力,去噪效果优于小波软阈值滤波方法;在消除测井信号随机噪声的同时,能很好地保留信号的波形和特征,在较低信噪比下仍可有效地提取测井信号的有用信息,提高了T2谱的反演精度。In nuclear magnetic resonance （ NMR ） logging, the echo signal is very weak while the background noise is strong.Thus it is difficult to separate signal and noise in the data.To scdve this problem,this work combined mathematical morphology and muhi-resolulion analysis of wavelet decomposition to generate a new de-noising method for NMR logging signals.called the morphological waw＇lel.This paper presents its principle and operalion steps. and compares its de-noising effect with thai of the wavelet soft-threshold method.The processing results of real logging data show thai this new method can preserve delails and resist against noise well, superior to the wavelet sofl-threshohl method. When il removes random noise,the signal waveforms and characteristics can be retained. Even in the case of low SNR, the useful information also can be effectiw.ly exlracted, which enhances the inversion precision of the T2 spectrum.

关 键 词：形态小波 核磁共振测井 小波软阈值 去噪 

分 类 号：P631[天文地球—地质矿产勘探]