海洋天然气水合物的弹性参数反演研究

Abstract: Physical property models of gas hydrate-bearing sediments and analysis of amplitude-versus-angle(AVA) character of bottom simulating reflector(BSR) are studied. The analysis of AVA character of BSR shows that different reflection coefficient values but similar configurations of AVA curves are given for different combinations of different concentrations of gas hydrate and free gas. Based on processing researches on real seismic data, the distribution character of Bottom-simulating reflector(BSR) on different seismic profiles is compared and described. Theoretical researches on inversion of elastic wave equation are conducted, then one pre-stack full waveform inversion method for gas hydrate-related bottom simulating reflector is proposed. High resolution velocity structures are obtained, and physical cause of occurrence of the double BSR in the eastern Nankai accretionary wedge has been given. Gas hydrates may exist in Dongsha islands area of the northern South China Sea from the comprehensive analyses of seismic, logging and geothermal data. These research works are important and will have wide application in extensive gas hydrate exploration, investigation and study

在矢量波动方程反演问题深入的理论研究基础上，建立切合海洋天然气水合物沉积实际的叠前地震道反演方法，获得高分辨率速度与弹性参数结构，进而建立估算天然气水合物的蕴藏量的方法并探讨其形成机制，对深入认识天然气水合物的资源潜力、对环境与灾害的影响具有重要的科学与实践意义。对地震反演研究的发展具有现实意义。