SEISMIC STUDIES OF MARINE GAS HYDRATES

We give a brief introduction of developments of seismic methods in the studies of marine gas hydrates. Then we give an example of seismic data processing for BSRs in western Nankai accretionary prism, a typical gas hydrate distribution region. Seismic data processing is proved to be important to obtain better images of BSRs distribution. Studies of velocity structure of hydrated sediments are useful for better understanding the distribution of gas hydrates. Using full waveform inversion, we successfully derived high-resolution velocity model of a double BSR in eastern Nankai Trough area. Recent survey and research show that gas hydrates occur in the marine sediments of the South China Sea and East China Sea.But we would like to say seismic researches on gas hydrate in China are very preliminary.

国外天然气水合物沉积学研究进展——以马利克和日本南海海槽为例

本文回顾了近年来国外在天然气水合物沉积学方面的研究进展，并以加拿大马利克（Mallik）以及日本南海海槽的水合物勘探实践为例进行了详细的阐述。在马利克的三角~J＇ISH的砂岩层中以及日本南海海槽的浊积砂岩层中都钻遇了高饱和度的天然气水合物，这表明高饱和度易于开发的天然气水合物优先在粗碎屑砂岩中富集，受沉积相控制明显，这一结论为天然气水合物沉积学的研究指明了方向。