In-situ detection of ocean floor seawater and gas hydrate exploration in the South China Sea

被引：0

作者：

Sun C. ^{[1
]}

Zhao H. ^{[1
,5
]}

He H. ^{[1
]}

Zhang Z. ^{[1
]}

Zhu W. ^{[1
]}

Sun X. ^{[2
,6
]}

Yin W. ^{[3
]}

Ling F. ^{[4
]}

机构：

[1] School of Engineering and Technology, China University of Geosciences(Beijing), Beijing

[2] School of Energy Resources, China University of Geosciences(Beijing), Beijing

[3] Geosun High-technology Company Limited, Changsha

[4] School of Geosciences and Info-physics, Central South University, Changsha

[5] No. 4 Gold Geological Party of CAPF, Liaoyang

[6] Bureau of Economic Geology, University of Texas at Austin, Austin

来源：

Earth Science Frontiers | 2017年 / 24卷 / 06期

关键词：

Gas hydrate; In-situ detection of seawater; Methane sensor; METS; Pore water; Stratified seawater;

D O I：

10.13745/j.esf.yx.2016-12-2

中图分类号：

学科分类号：

摘要：

Based on the analysis of in-situ detection technology of ocean floor seawater in China and abroad, this article introduces a self-developed product used in the in-situ measurement of water-soluble methane, and elaborates on the research idea, key technical points and differences from technology used abroad. We have collected a large amount of data of water-soluble methane in the north of the South China Sea, including in the surface and bottom seawaters, and in-situ exploratory data by our own product. Aimed at providing a reference for the geochemical prospecting of marine gas hydrate, we have compared the geochemical characteristics of stratified seawater-mainly about methane concentration, analyzed different seawater detection technologies and evaluated their significance when used as important indicators in gas hydrate exploration. The results show that: (1) there is a medium level methane concentration of about 10-50 nmol·L-1 and a large area of methane geochemical anomaly (>1000 km2) of surface seawater in the gas hydrate prospect areas; (2) the bottom seawater has a certain regional methane geochemical anomaly and the methane anomaly background value is above 100 nmol·L-1; and (3) the in-situ detection of bottom seawater has an extra-high level methane concentration of about 300-800 nmol·L-1 in the hydrate bearing area. The achievements of the exploration technologies in fluid geochemistry reveal that: (1) the methane anomaly obtained from surface seawater by the conventional techniques and CTD are helpful for finding the exploration prospect areas of gas hydrate; and (2) the methane anomaly of bottom seawater detected by in-situ online and core top seawater has a strong correlation with hydrocarbon seepage below the seafloor, and the isotopic characteristics indicate that we can seek out and identify methane seepage zone related to gas hydrate through biogenic methane. We believe the in-situ geochemical exploration technology has a promising prospect of application in finding marine gas hydrate. © 2017, Editorial Office of Earth Science Frontiers. All right reserved.

引用

页码：225 / 241

页数：16

共 7 条

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