Natural gas hydrate samples were successfully recovered from Shenhu area on the northern margin of the South China Sea in 2007. A series of research projects were carried out in the laboratory to investigate the basic characteristics (i.e., the structure, gas composition, gas content and saturation) of the hydrate samples using various analytical techniques. The results show that the gas hydrates are a typical structure I (sI) hydrate, with occupancy rates of methane being more than 99% in large cage and ~86% in small cage, corresponding to a hydration number of 5.99. The guest molecules in hydrate cages are predominantly methane (> 99.3%). The saturation of gas hydrate in the sediments is found to be around 21%, which is lower than that observed in the field. The relatively low percentage is due to free water in the sediment, which affects the measurement of the ratio of gas to water.
LIU Chang-ling
,
YE Yu-guang
,
MENG Qing-guo
,
HE Xing-liang
,
CHEN Qiang
,
HU Gao-wei
. Characteristics of gas hydrate samples recovered from Shenhu Area in the South China Sea[J]. Journal of Tropical Oceanography, 2012
, 31(5)
: 1
-5
.
DOI: 10.11978/j.issn.1009-5470.2012.05.001
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