Velocity Structure of Bottom Simulating Reflectors in Northern South China Sea from Full Waveform Inversion

• 责任者：Huo Yuanyuan (Exploration and Development Institute ; North-China Branch Company ; SINOPEC ; Zhengzhou 450006 ; China) ; Zhang Ming
• 刊名：Computing Techniques for Geophysical and Geochemical Exploration
• 出版年：2010
• 卷期：32(2)
• 关键词：似海底反射层 ; bottom-similating reflectors ; 天然气水合物 ; gas hydrates ; 南海 ; South China Sea
• 页码：p.182-187
• 图表：3 illus., 36 refs.
• 分类号：1500, 1003
• issnNo：ISSN1001-1749
• isbnNo：CN51-1242/P

Bottom Simulating Reflectors (BSRs) is considered as an identifier of gas hydrate and free gas. In order to obtain accurate velocity structure of BSRs, this paper presents a full waveform inversion strategy based on genetic algorithm. This method is divided into two parts: global search and local search. This method is applied to field data from northern South China Sea. Inversion results show that obvious velocity anomaly of BSRs can be detected, which indicates the existence of gas hydrate and free gas. The resulting compressional velocity is used to estimate gas content in the sediments. And the source of methane gas in this region is both thermogenic gas and biogenic gas.