南海北部陆坡天然气水合物成藏特征研究进展分析

南海北部陆坡区域构造地质控制着气源、流体疏导体系、富集空间及储层物性特征,因此,东沙海域、神狐海域、西沙海槽和琼东南盆地的水合物成藏条件及控制因素具有明显差异性。东沙海域深部气体可沿断层、裂缝、不整合面、砂岩疏导层和气烟囱等通道向上运移,并形成天然气水合物,具有渗漏型水合物产出特征;神狐海域水合物成藏与规模巨大的泥底辟活动相关,并与布莱克海台天然气水合物产出特征具有相似性;琼东南盆地中央坳陷带内为天然气水合物发育的重点区,底辟、泥火山或麻坑构造与天然气水合物发育密切相关。

Research Progress on Gas Hydrate Accumulation in the Northern Slope of the South China Sea

The tectonic geology of the northern slope of the South China Sea determines the gas source, fluid drainage system, enrichment space, and reservoir physical characteristics. Therefore, the hydrate accumulation conditions and control factors of Dongsha Area, Shenhu Area, Xisha Trough, and Qiongdongnan Basin are significantly different. The deep gas in the Dongsha Area can be moved up along the faults, cracks, unconformity surfaces, sandstone drainage layers and gas chimneys, and form natural gas hydrates in shallow sediments, which has the characteristics of venting-type hydrate. The hydrate accumulation in the Shenhu Area is related to the large-scale mud diapir activity and is similar to that of gas hydrate in the Blake ridge. The central depression of Qiongdongnan Basin is the key area for gas hydrate development. The diapir, mud volcano or pockmarks are closely related to the gas hydrates.