Crystallographic and geochemical properties of natural gas hydrates accumulated in the National Gas Hydrate Program Expedition 02 drilling sites in the Krishna-Godavari Basin off India
Crystallographic and geochemical properties of natural gas hydrates accumulated in the National Gas Hydrate Program Expedition 02 drilling sites in the Krishna-Godavari Basin off India
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印度克里希纳-戈达瓦里盆地国家天然气水合物计划第 02 号勘探钻探场积累的天然气水合物的晶体学和地球化学特性
DOI：
10.1016/j.marpetgeo.2018.10.012
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发表时间：
2019
影响因子：
4.2
通讯作者：
N. Tenma
中科院分区：
文献类型：
--
作者：
Masato Kida;Yusuke Jin;J. Yoneda;M. Oshima;A. Kato;Y. Konno;J. Nagao;N. Tenma
本研究介绍了国家天然气水合物计划 (NGHP) 第 02 次探险期间在印度东部克里希纳-戈达瓦里盆地三个研究区通过压力岩心作业回收的不同类型孔隙空间天然气水合物的晶体学和地球化学特性。天然气水合物为结构I，水合数n=6.1-6.2，主要由微生物甲烷和少量C3以下的重质烃形成。无论沉积物孔隙大小如何，水合物晶格常数几乎是均匀的。乙烷浓度随粘土含量和一定深度而变化，其测量有助于解决溶解在孔隙水中的气体对水合物形成的贡献。我们还使用衍射技术和含水合物沉积物的目视观察来评估钻探对岩心的干扰。
This study presents the crystallographic and geochemical properties of different types of pore-space natural gas hydrate recovered by pressure core operations during the National Gas Hydrate Program (NGHP) Expedition 02 at three study areas in the Krishna-Godavari Basin off eastern India. The gas hydrate is structure I with hydration numbern= 6.1–6.2, formed predominantly from microbial methane and small amounts of heavier hydrocarbons up to C3. Hydrate crystal lattice constants are nearly uniform regardless of sediment pore-space size. Ethane concentration varies with clay content and to some extent depth, and its measurement helps resolve the contributions of gases dissolved in pore water to hydrate formation. We also assess the disturbance of the core through drilling, using diffraction techniques and visual observation of hydrate-bearing sediments.