海底天然气水合物地震研究方法及海底地震仪的应用

为促进水合物地震探测和研究方法的深入，在对已有研究方法（直接法、叠加速度分析法、ＡＶＯ、全波形反演）进行综合分析的基础上，针对原方法中存在的问题，提出了用海底地震仪（OBS）开展层析成像的方法和技术思路。首先对OBS的走时和波形联合反演的方法、水合物地震层析成像技术作了介绍；其次，分析了该方法存在没有或不能充分利用海底震仪的三分量记录，尤其是S波信息，没有真正意义上的3D资料，没有开展更深部的探查（仅限于似海底反射界面）等问题；最后，提出发展和完善OBS地震层析成像技术研究水合物、游离气以及碳氢化合物的深部迁移通道的初步设想和技术方案。这对海洋天然气水合物的勘探有一定的指导作用。

SEISMIC METHODS AND OBS APPLICATION IN THE STUDY OF OCEANIC GAS HYDRATES

In order to improve the seismic prospecting and research method for gas hydrates,based on the integrative analysis on the existing methods(including direct method,stack velocity analysis method,AVO,and full waveform inversion method),and aimed at the problems of these methods,the paper put forward the method and technical idea of tomographic imaging technique with Ocean Bottom Seismometers(OBS).First,the paper introduced the joint inversion method of the travel time and waveform,and seismic tomographic imaging technique for gas hydrates by using Ocean Bottom Seismometers;secondly,the paper analyzed that the above methods don't use or fully use the three component records,especially S wave information,which are acquired with OBS.Moreover,the paper indicated this method is not real 3D,and doesn't involve the deeper layers prospecting(only limited in the reflection interfaces in the quasi ocean bottom).Finally,the paper brought forward the preliminary idea and technical scheme for studying the deep migration channel of the gas hydrates,free gas,and hydrocarbon by developing and improving OBS seismic tomographic imaging technique,which plays some role of guiding for ocean gas hydrate exploration.