南海北部天然气水合物成藏地质条件及成因模式探讨

Geological background and accumulation models of gas hydrate reservoir in northern South China Sea

中国南海北部陆坡区是天然气水合物成藏的理想场所,资源潜力巨大。文章基于天然气水合物勘探成果,结合南海北部天然气水合物成藏地质背景,从天然气水合物成藏的温压稳定条件、气源形成条件、构造输导条件和沉积储集条件4方面,系统分析了南海北部天然气水合物成藏的基本地质条件,探讨了南海北部陆坡中部神狐海域、南海北部陆坡西部海域和南海北部陆坡东北部海域天然气水合物的成藏类型与成因模式。结果认为,南海北部陆坡中部神狐海域主要发育扩散型水合物,而南海北部陆坡西部海域主要发育渗漏型水合物,南海北部陆坡东北部海域则发育兼具扩散型与渗漏型特征的复合型水合物。

Exploration results reveal that the northern slope of South China Sea(SCS)is a favorable area for gas hydrateaccumulation and hence has huge energy resources potential.Based on the results of gas hydrate exploration conducted in northernSCS and geological background of gas hydrate reservoir in the study area,the authors analyzed the conditions of temperaturepressurestability,gas source supply,migration conduction system and reservoir for gas hydrate accumulation in northern SCS.Moreover,the accumulation models of gas hydrate reservoir in Shenhu,the western slope of South China Sea areas and thenortheastern slope of South China Sea areas were discussed as well.The results show that the diffusion gas hydrate reservoir ismainly accumulated in Shenhu area,while the western slope of South China Sea area is dominated by the leakage type of reservoir.On the northeastern slope of South China Sea area,gas hydrate accumulation is complex and is characterized by both diffusion and leakage types.