Comparison of Different-Type Heat Flows at Typical Sites in Natural Gas Hydrate Exploration Area on the Northern Slope of the South China Sea

详细信息   

• 责任者：Xu Xing(Guangzhou Marine Geological Survey ; Guangzhou 510760 ; China) ; Li Yamin
• 刊名：Chinese Journal of Geophysics
• 出版年：2012
• 卷期：55(3)
• 关键词：天然气水合物 ; gas hydrates ; 热流 ; heat flow ; 南海 ; South China Sea
• 页码：p.998-1006
• 图表：4 illus., 33 tables, 5 refs.
• 分类号：1003
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

摘要

In the natural gas hydrate exploration on the northern slope of the South China Sea,three types of heat flow data were derived from drilling measurement,probe measurement,and BSR measurement.To investigate the differences of different seafloor heat flow measurement methods and the characteristics of natural gas hydrate exploration area on the northern slope of the South China Sea,the paper takes SH-2 and SH-5,the two wells for natural gas hydrate exploration,as the typical sites to describe the three heat flow measurement methods and compare the results at the two sites.The following results were gotten.First,the probe-type heat flow is almost identical with drilling-type heat flow at Site SH-2,but is lower obviously at Site SH-5;BSR-type heat flows calculated with actual average heat-conductivity are almost identical with drilling-type heat flows at both Site SH-2 and Site SH-5.Second,the obviously lower probe-type heat flow than drilling-type heat flow at Site SH-5 might be caused by liquid activities,as indicated by analysis of the characteristics of seismic profile and heat flow of neighboring sites.Third,the Site SH-5 has higher geothermal gradient and heat flow than Site SH-2,which may be an important reason of failure to get hydrate at Site SH-5.Furthermore,it may be the late-stage diapir that brought higher temperature and decomposed the former hydrate at Site SH-5.