中文摘要：

在海域天然气水合物勘探过程中,全波形反演可以在缺少井资料情况下提供水合物及游离气区域精细速度结构,与AVO分析相比,全波形反演可以有效降低薄层效应影响.概述了全波形反演的研究进展及其在海域天然气水合物参数结构分析中的应用现状;讨论了天然气水合物全波形反演策略,包括基于层状介质假设的全局优化与局部优化相结合反演策略和基于有限差分、有限元正演模拟的多参数结构直接反演策略等;探讨了天然气水合物全波形反演中一些具有代表性的技术特点,包括地震子波估计方式、海底多分量地震数据的应用、多参数同时反演;最后给出天然气水合物全波形反演发展趋势和可能改进建议.随着三维全波形反演算法的不断改进,海域天然气水合物勘探精度将进一步提高,为水合物商业开发提供依据.

英文摘要：

In the process of natural gas hydrate exploration,full waveform inversion（FWI）can provide detailed velocity structure of the hydrate and free gas zone,even in the absence of well data.Compared with the AVO analysis,the full waveform inversion can effectively reduce the tuning effect,because the full waveform inversion method utilizes both amplitude and waveform information.In our study, we summarized the research progress of the FWI and its application status in the parameter structure analysis of marine natural gas hydrate.And we discussed on the strategies of the FWI in natural gas hydrate exploration,not only the strategy which is the combination of global optimization and local optimization based on the assumption of layered medium,but also the multiparameter structure directly inversion strategy which is based on the finite difference or finite element full-wavefield modeling methods. Also we discussed about some key technical characteristics such as source wavelet estimating methods,the application of submarine multi-component seismic data and multi-parameter simultaneous inversion technique which account for parameter classes other than P-wave velocity,such as S-wave velocity, density,attenuation and anisotropy.Finally,we pointed out the development trend and some possible improvement suggestions for natural gas hydrate FWI.We proposed joint application of Laplace-domain FWI and Laplace-Fourier-domain FWI to the natural gas hydrate exploration,which beginning with a very crude starting model,and it＇s necessary to do further study to prove its feasibility.The 3-D FWI will be possibly applied in natural gas hydrate seismic exploration with the forward modeling is more efficiently through source assembling and phase encoding techniques, which can provide reference for commercial development of marine gas hydrate.