Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea

doi:10.1029/2010JB007944

CORC > 海洋研究所 > 中国科学院海洋研究所 > 海洋地质与环境重点实验室

	Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea
	Wang, Xiujuan 1,2; Hutchinson, Deborah R.3; Wu, Shiguo 1,2; Yang, Shengxiong 4; Guo, Yiqun 4; Wang, XJ (reprint author), Chinese Acad Sci, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
	2011-05-25
卷号	116 页码:B05102
ISSN号	0148-0227
DOI	10.1029/2010JB007944
文献子类	Article
英文摘要	Gas hydrate saturations were estimated using five different methods in silt and silty clay foraminiferous sediments from drill hole SH2 in the South China Sea. Gas hydrate saturations derived from observed pore water chloride values in core samples range from 10 to 45% of the pore space at 190-221 m below seafloor (mbsf). Gas hydrate saturations estimated from resistivity (R-t) using wireline logging results are similar and range from 10 to 40.5% in the pore space. Gas hydrate saturations were also estimated by P wave velocity obtained during wireline logging by using a simplified three-phase equation (STPE) and effective medium theory (EMT) models. Gas hydrate saturations obtained from the STPE velocity model (41.0% maximum) are slightly higher than those calculated with the EMT velocity model (38.5% maximum). Methane analysis from a 69 cm long depressurized core from the hydrate-bearing sediment zone indicates that gas hydrate saturation is about 27.08% of the pore space at 197.5 mbsf. Results from the five methods show similar values and nearly identical trends in gas hydrate saturations above the base of the gas hydrate stability zone at depths of 190 to 221 mbsf. Gas hydrate occurs within units of clayey slit and silt containing abundant calcareous nannofossils and foraminifer, which increase the porosities of the fine-grained sediments and provide space for enhanced gas hydrate formation. In addition, gas chimneys, faults, and fractures identified from three-dimensional (3-D) and high-resolution two-dimensional (2-D) seismic data provide pathways for fluids migrating into the gas hydrate stability zone which transport methane for the formation of gas hydrate. Sedimentation and local canyon migration may contribute to higher gas hydrate saturations near the base of the stability zone.; Gas hydrate saturations were estimated using five different methods in silt and silty clay foraminiferous sediments from drill hole SH2 in the South China Sea. Gas hydrate saturations derived from observed pore water chloride values in core samples range from 10 to 45% of the pore space at 190-221 m below seafloor (mbsf). Gas hydrate saturations estimated from resistivity (R(t)) using wireline logging results are similar and range from 10 to 40.5% in the pore space. Gas hydrate saturations were also estimated by P wave velocity obtained during wireline logging by using a simplified three-phase equation (STPE) and effective medium theory (EMT) models. Gas hydrate saturations obtained from the STPE velocity model (41.0% maximum) are slightly higher than those calculated with the EMT velocity model (38.5% maximum). Methane analysis from a 69 cm long depressurized core from the hydrate-bearing sediment zone indicates that gas hydrate saturation is about 27.08% of the pore space at 197.5 mbsf. Results from the five methods show similar values and nearly identical trends in gas hydrate saturations above the base of the gas hydrate stability zone at depths of 190 to 221 mbsf. Gas hydrate occurs within units of clayey slit and silt containing abundant calcareous nannofossils and foraminifer, which increase the porosities of the fine-grained sediments and provide space for enhanced gas hydrate formation. In addition, gas chimneys, faults, and fractures identified from three-dimensional (3-D) and high-resolution two-dimensional (2-D) seismic data provide pathways for fluids migrating into the gas hydrate stability zone which transport methane for the formation of gas hydrate. Sedimentation and local canyon migration may contribute to higher gas hydrate saturations near the base of the stability zone.
学科主题	Geochemistry & Geophysics
URL标识	查看原文
语种	英语
WOS记录号	WOS:000291107000001
公开日期	2012-07-03
内容类型	期刊论文
源URL	[http://ir.qdio.ac.cn/handle/337002/11548]
专题	海洋研究所_海洋地质与环境重点实验室
通讯作者	Wang, XJ (reprint author), Chinese Acad Sci, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China
作者单位	1.Chinese Acad Sci, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China 2.Chinese Acad Sci, Inst Oceanol, Qingdao 266071, Peoples R China 3.US Geol Survey, Woods Hole, MA 02543 USA 4.Guangzhou Marine Geol Survey, MLR, Guangzhou 510760, Guangdong, Peoples R China
推荐引用方式 GB/T 7714	Wang, Xiujuan,Hutchinson, Deborah R.,Wu, Shiguo,et al. Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2011,116:B05102.
APA	Wang, Xiujuan,Hutchinson, Deborah R.,Wu, Shiguo,Yang, Shengxiong,Guo, Yiqun,&Wang, XJ .(2011).Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,116,B05102.
MLA	Wang, Xiujuan,et al."Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 116(2011):B05102.