The Mechanism of Methane Gas Migration Through the Gas Hydrate Stability Zone: Insights From Numerical Simulations

doi:10.1029/2019JB017417

CORC > 南海海洋研究所 > 中国科学院南海海洋研究所 > 中科院边缘海地质重点实验室

	The Mechanism of Methane Gas Migration Through the Gas Hydrate Stability Zone: Insights From Numerical Simulations
	Liu, Jinlong 2,3; Haeckel, Matthias 3; Rutqvist, Jonny 1; Wang, Shuhong ; Yan, Wen 2
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
	2019
卷号	124 期号:5 页码:4399
关键词	fluid flow gas seepage gas migration pathways gas hydrate numerical modeling
ISSN号	2169-9313
DOI	10.1029/2019JB017417
英文摘要	Free gas migration through the gas hydrate stability zone (GHSZ) and subsequent gas seepage at the seabed are characteristic features in marine gas hydrate provinces worldwide. The biogenic or thermogenic gas is typically transported along faults from deeper sediment strata to the GHSZ. Several mechanisms have been proposed to explain free gas transport through the GHSZ. While inhibition of hydrate formation by elevated salinities and temperatures have been addressed previously in studies simulating unfocused, area-wide upward advection of gas, which is not adequately supported by field observations, the role of focused gas flow through chimney-like structures has been underappreciated in this context. Our simulations suggest that gas migration through the GHSZ is, fundamentally, a result of methane gas supply in excess of its consumption by hydrate formation. The required high gas flux is driven by local overpressure, built up from gas accumulating below the base of the GHSZ that fractures the overburden when exceeding a critical pressure, thereby creating the chimney-like migration pathway. Initially rapid hydrate formation raises the temperature in the chimney structure, thereby facilitating further gas transport through the GHSZ. As a consequence, high hydrate saturations form preferentially close to the seafloor, where temperatures drop to bottom water values, producing a prominent subsurface salinity peak. Over time, hydrates form at a lower rate throughout the chimney structure, while initial temperature elevation and salinity peak dissipate. Thus, our simulations suggest that the near-surface salinity peak and elevated temperatures are a result of transient high-flux gas migration through the GHSZ.
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/17958]
专题	南海海洋研究所_中科院边缘海地质重点实验室
作者单位	1.GEOMAR Helmholtz Ctr Ocean Res Kiel, Kiel, Germany 2.Chinese Acad Sci, South China Sea Inst Oceanol, CAS Key Lab Ocean & Marginal Sea Geol, Guangzhou, Guangdong, Peoples R China 3.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing, Peoples R China 4.Lawrence Berkeley Natl Lab, Berkeley, CA USA
推荐引用方式 GB/T 7714	Liu, Jinlong,Haeckel, Matthias,Rutqvist, Jonny,et al. The Mechanism of Methane Gas Migration Through the Gas Hydrate Stability Zone: Insights From Numerical Simulations[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2019,124(5):4399, 4427.
APA	Liu, Jinlong,Haeckel, Matthias,Rutqvist, Jonny,Wang, Shuhong,&Yan, Wen.(2019).The Mechanism of Methane Gas Migration Through the Gas Hydrate Stability Zone: Insights From Numerical Simulations.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,124(5),4399.
MLA	Liu, Jinlong,et al."The Mechanism of Methane Gas Migration Through the Gas Hydrate Stability Zone: Insights From Numerical Simulations".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 124.5(2019):4399.