摘要
中国是世界上少数几个同时在海域和陆域冻土区取得天然气水合物找矿突破的国家,这为我国天然气水合物成矿气源研究提供了良好的研究条件。本文通过对南海神狐海域及祁连山冻土区不同层位、不同赋存状态的水合物气体数据进行分析,研究了各层位烃类气体的地球化学特征,并探讨其成因。研究结果表明,海域和陆域钻孔岩心游离气与水合物气具有基本一致的气体组分特征和同位素特征,表明气体成因类型相同。同一钻孔中,气体随埋深不同表现出不同的气体组分特征,甲烷碳同位素显示负偏,均表明气体存在垂向运移。岩心游离气对水合物成因类型判识具有指示意义,可作为判识水合物或潜在水合物成因类型的一种有效方法。
China is one of the few countries in the world which have made breakthroughs in discovery of gas hydrate in both offshore and inland.It has therefore provided good platforms for study of gas origins.In this paper,we collected the data from different layers and different occurrences of the Shenhu area,South China Sea and the permafrost region in the Qilian Mountains.Geochemical studies of hydrocarbon gas are carried out for gas origin.Our results indicate that free gas from drilling cores is of significance and effective to the identification of genetic-type and origin of gas hydrates.If the composition and isotopic characteristics of the free gas are identified with the gas hydrate,it indicates a consistent gas origin.However,if there shows difference in gas composition characteristics and that there is negative deviation of methane carbon isotope in a vertical sequence for the same hole,it means there is vertical migration.As the conclusion,free gas can provide effective information for identifying hydrate or its genetic types.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2017年第5期82-89,共8页
Marine Geology & Quaternary Geology
基金
国家自然科学基金项目(41202099)
