Distribution Characteristics and Origin of Hydrocarbon Gas from the Borehole QK-1 in the Qiangtang Basin, Qinghai-Tibetan Plateau
详细信息
- 责任者：Yang Kaili (Institute of Mineral Resources ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Zhu Youhai
- 刊名：Geoscience
- 出版年：2013
- 卷期：27(2)
- 关键词：烃气测量 ; hydrocarbon surveys ; 天然气水合物 ; gas hydrates ; 羌塘盆地 ; Qiangtang Basin
- 页码：p.405-412
- 图表：illus., 1 table, 29 refs.
- 分类号：1500
- issnNo：ISSN1000-8527
- isbnNo：CN11-2035/P
摘要
The Qinghai-Tibetan Plateau is the largest permafrost in China with an area of 150×104 km2,which is favorable for the formation and accumulation of natural gas hydrate,and the Qiangtang Basin will be the best target with a good prospect for natural gas hydrate reservoirs.The hydrocarbon gas composition and carbon isotope of the headspace gas samples from the borehole QK-1,one of the scientific drilling holes of gas hydrate in the Biluocuo area of the southern Qiangtang Basin,were determined and analyzed.The results indicate the hydrocarbon gas composition is complex,and the methane concentrations range from 3.0×10-6 to 4,526.8×10-6 with the average being 209.0×10-6.The δ13C values of methane range from-55.9‰ to-37.8‰ with the average being-43.2‰,and the values of C1/(C2+C3) are lower than 10,obviously suggesting thermogenic gas characteristics.According to the geological background and lithologic characteristics of the drilling area,it is estimated that the hydrocarbon gas comes from the deeper thermogenic gas which has migrated upward from the deep place,and may be mixed with biogenic gas in the shallow.