| Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea | |
| Wang, Xiujuan1,2; Hutchinson, Deborah R.3; Wu, Shiguo1,2; Yang, Shengxiong4; Guo, Yiqun4; Wang, XJ (reprint author), Chinese Acad Sci, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China | |
| 2011-05-25 | |
| 发表期刊 | JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
 |
| ISSN | 0148-0227 |
| 卷号 | 116页码:B05102 |
| 文章类型 | Article |
| 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. |
| 学科领域 | Geochemistry & Geophysics |
| DOI | 10.1029/2010JB007944 |
| URL | 查看原文 |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000291107000001 |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://ir.qdio.ac.cn/handle/337002/11547 |
| 专题 | 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 |
| 第一作者单位 | 中国科学院海洋研究所 |
| 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. |
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