Distribution and characteristics of natural gas hydrates in the Shenhu Sea Area, South China Sea
Distribution and characteristics of natural gas hydrates in the Shenhu Sea Area, South China Sea
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南海神狐海域天然气水合物分布及特征
DOI：
10.1016/j.marpetgeo.2018.07.028
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发表时间：
2018-12
影响因子：
4.2
通讯作者：
尉建功
中科院分区：
文献类型：
--
作者：
尉建功
构造类型、气体组成和笼型占有是重要的天然气水合物特征，对计算天然气水合物稳定性和估算全球水合物结合甲烷量具有重要作用。2016年，中国在南海神狐海域（SSA）开展了第四次天然气水合物钻井活动（GMGS4），获得了综合随钻测井（LWD）数据和天然气水合物样品。随钻测井资料显示，各深度的电阻率和声速均较高，表明该区域存在天然气水合物。利用拉曼光谱分析首次证实了南海I型（sI）和II型（sII）天然气水合物共存。水合物sI中大笼和小笼的甲烷笼度分别为0.95和0.96。sI水合物的水化数为6.03。气体成分分析表明，甲烷（>98.7%）为主要气体，少量重烃气体（乙烷：0.006% ~ 0.976%，丙烷：0.033% ~ 0.216%，异丁烷：0.004% ~ 0.047%）和其他非烃气体（二氧化碳：<0.008%）。天然气组成（C1/(C2+C3): 84 ~ 2333）和同位素组成（δ13C: - 50.9‰~ -46.46‰，δD: - 177.69‰~ -148.90‰）表明水合物结合气以热源为主，并伴有一定数量的生物源。sII水合物的存在可能加深了海洋沉积物中sI天然气水合物稳定带的基础。sI和sII天然气水合物的共存增加了天然气-水-水合物体系的复杂性，在研究天然气水合物分布、估计全球天然水合物结合气总量和模拟天然气产量时需要考虑这一复杂性。
Structure type, gas composition and cage occupancy are important gas hydrate characteristics which play an important role in calculating gas hydrate stability and estimating the amount of global hydrate-bound methane. China conducted the Fourth gas hydrate drilling campaign (GMGS4) in the Shenhu Sea Area (SSA) of the South China Sea in 2016, during which comprehensive Logging-While-Drilling (LWD) data and natural gas hydrate samples were obtained. The LWD data shows high electrical resistivity and high sound velocity at various depth, indicating the occurrence of gas hydrate in this area. Coexistence of structure I (sI) and structure II (sII) gas hydrates in the South China Sea was confirmed for the first time by using Raman spectra analysis. The methane cage occupancies of large cages and small cages in sI hydrate are 0.95 and 0.96, respectively. The hydration number of sI hydrate is 6.03. Gas composition analysis shows that methane (>98.7%) is the dominate gas, with small amount of heavier hydrocarbon gases (ethane: 0.006%–0.976%, propane: 0.033%–0.216%, isobutane: 0.004%–0.047%) and other non-hydrocarbon gases (carbon dioxide: <0.008%). Gas composition (C1/(C2+C3): 84–2333) and isotope composition (δ13C: −50.9‰∼-46.46‰, δD: −177.69‰∼-148.90‰) indicate hydrate-bound gas is dominated by thermogenic source, mixed with certain amount of biogenic source. Existence of sII hydrate potentially deepen the base of sI gas hydrate stability zone in the marine sediment. Coexistence of sI and sII gas hydrates increases the complexity of the gas-water-hydrate system which need to be considered when studying the gas hydrate distribution, estimating the amount of global natural hydrate-bound gases and modeling the gas production.
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影响因子：
2.9
作者：
G. Bohrmann;W. Kuhs;S. A. Klapp;K. Techmer;H. Klein;M. M. Murshed-M.;F. Abegg
通讯作者：
G. Bohrmann;W. Kuhs;S. A. Klapp;K. Techmer;H. Klein;M. M. Murshed-M.;F. Abegg
影响因子：
3.9
作者：
Lu, HL;Moudrakovski, I;Dallimore, S
通讯作者：
Dallimore, S
影响因子：
4.9
作者：
E. Piñero;M. Marquardt;C. Hensen;M. Haeckel;K. Wallmann
通讯作者：
E. Piñero;M. Marquardt;C. Hensen;M. Haeckel;K. Wallmann
影响因子：
5.3
作者：
Dickens, GR
通讯作者：
Dickens, GR
影响因子：
3.3
作者：
Sum, AK;Burruss, RC;Sloan, ED
通讯作者：
Sloan, ED