基于CEEMDAN的希尔伯特变换在海底天然气水合物地震探测中的应用  

Application of Hilbert Transform in Seismic Exploration of Submarine Gas Hydrate Based on CEEMDAN

作　　者：夏秋萍 刘怀山[1,2] Xia Qiuping;Liu Huaishan(Key Lab of Submarine Geosciences and Prospecting Techniques, Ministry of Education,Ocean University of China, Qingdao Shandong 266100, China;Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao Shandong 266071, China)

机构地区：[1]中国海洋大学海底科学与探测技术教育部重点实验室,山东青岛266100 [2]海洋国家实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266071

出　　处：《工程地球物理学报》2022年第1期27-34,共8页Chinese Journal of Engineering Geophysics

基　　金：国家自然科学基金(编号:91958206);国家重点研发计划(编号:2017YFC0307401)。

摘　　要：当地层中填充了天然气水合物后,沉积物的一些物理性质会发生相应的改变,最终引起地震属性的变化,因此地震属性中包含了大量地质特征,是识别海底地层是否存在天然气水合物的一个重要标志。通常用来识别天然气水合物的瞬时振幅、相位、频率可以应用希尔伯特变换来获得,但单纯的希尔伯特变换获得的瞬时属性有效信息较少,为了获得更高的分辨率,提出了基于EMD算法的希尔伯特变换,由于EMD算法模态混叠严重,最终提出了改进后的CEEMDAN算法。本文利用CEEMDAN算法对地震属性信号进行分解,选择了包含有效信息的IMF分量与希尔伯特变换相结合,获得了瞬时属性,将方法用于OBS(海底地震仪)和垂直缆的天然气水合物数据中,得到的属性结果分辨率较高,清晰地表明了海底似反射BSR(Bottom Simulating Reflector)的瞬时振幅和频率信息,为识别天然气水合物提供了依据。When the formation is filled with natural gas hydrate,some physical properties of sediments will change accordingly,resulting in changes in seismic attributes.Therefore,seismic attributes contain a large number of geological features,which is an important sign to identify whether there is natural gas hydrate in seabed strata.By analyzing seismic attributes,it can be identified whether there are natural gas hydrates in the seafloor formation.Generally used to identify the instantaneous amplitude,phase,and frequency of natural gas hydrates,the Hilbert transform can be used to obtain it,but the simple Hilbert transform can obtain less effective information about the instantaneous attributes.In order to obtain higher resolution,Hilbert transform based on the EMD algorithm is presented.Due to the serious modal aliasing of the EMD algorithm,an improved CEEMDAN algorithm is finally proposed.In this paper,the CEEMDAN algorithm is used to decompose the seismic attribute signal,and the IMF component containing effective information is selected to combine with the Hilbert transform to obtain the instantaneous attributes.The method is used in the gas hydrate data of vertical cables and seabed seismometers.The seismic instantaneous attributes of natural gas hydrates with high resolution and clear profiles are obtained,which provides a basis for identifying natural gas hydrates.

关 键 词：CEEMDAN HILBERT变换 天然气水合物 瞬时属性 

分 类 号：P631.4[天文地球—地质矿产勘探]