海底电缆多波多分量三维多尺度时间域全波形反演研究

项目名称： 海底电缆多波多分量三维多尺度时间域全波形反演研究

项目编号： No.41504102

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 成景旺

作者单位： 长江大学

项目金额： 20万元

中文摘要： 全波形反演要求提供全方位角、大偏移距的地震数据，而三维海底电缆（OBC）观测系统具有天然适应这一要求的特点。三维OBC采集系统中震源密集、检波器分布广，且全波形反演自身存在多解性，因此计算任务重、内存需求大、计算效率低及反演的不稳定性是制约三维OBC多波多分量全波形反演由理论转化为应用的关键因素。针对这一问题，本项目提出了基于区域分解的三维多尺度时间域全波形反演方法。采用基于MPI并行平台的分布式内存技术解决内存不足，同时提高计算效率；采用合适的滤波器对时间域波场进行滤波，从低频带到高频带依次反演实现时间域多尺度反演，以减少解的非唯一性；通过理论模型的合成记录，研究分析不同的海底OBC多波多分量数据对海底速度反演结果的影响以及多震源混合激发参数对三维OBC全波形反演的影响，为我国三维OBC多波多分量全波形反演的实现提供理论方法与技术支持。

中文关键词： 全波形反演；多波多分量；海底电缆；三维时间域；多尺度

英文摘要： It needs a full-azimuth and large offset seismic data for full waveform inversion, and the 3D ocean bottom cable(OBC) survey system quietly meets the requirement. However, the OBC survey system with intensive source and wide distribution detector will lead to heavy calculation, large required memory, and the low computational efficiency. In addtion, full waveform inversion itself has the non-uniqueness. These key factors restricte the development of the 3D OBC multi-wave and multi-component full waveform inversion from theory to application. To solve this problem, this project proposes a multi-scale method for 3D time-domain full waveform inversion based on domain decomposition. Use distributed memory which based on MPI parallel platform to solve insufficient memory, and at the same time to improve computational efficiency. Adopt appropriate low-pass filter for filtering the time-domain wavefiled. By constantly improving the low-pass cutoff frequency for time-domain multiscale inversion from low-frequency inversion band to high-frequency inversion band to reduce the non-uniqueness of the solution. Through numerical tests on the theoretical model, we analysis the effect of the different OBC multi-wave and multi-component data and multi-source parameters on 3D OBC full waveform inversion, which can provide theoretical method and technology support to realize 3D OBC multi-wave and multi-component full waveform inversion for our country.

英文关键词： Full waveform inversion;Multi-wave and Multi-component;Ocean bottom cable;3D time-domain;Multiscale