Numerical computation and case analysis of the venting process of free gas beneath hydrate layer

doi:10.3969/j.issn.0001-5733.2009.12.022

GIEC OpenIR > 中国科学院广州能源研究所

	Numerical computation and case analysis of the venting process of free gas beneath hydrate layer
	Su Zheng1,3 ; Cao Yun-Cheng 1; Wu Neng-You1,3 ; Cathles, Lawrence M.2; Chen Duo-Fu 1,3
	2009-12-01
发表期刊	CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
卷号	52 期号:12 页码:3124-3131
摘要	A hydrate layer is an ideal capillary seal, beneath which free gas is trapped. Gas overpressure increases as gas accumulates and gas column grows. Capillary I seals have the property that they fall completely when gas pressure reaches the point that they are invaded by gas, and thereafter they offer little resistance to gas venting. After the seepage is triggered, the venting gas will push the overlying water upward at increasingly higher velocities as the gas "piston" approaches the seafloor. Numerical model shows that as the water velocity increases the near surface sediments will become quick at a depth that the resistance of water flow exceeds the hydrostatic pressure of the sediment hosting the water flow. These quick sediments can then be removed by bottom ocean currents, leaving a hollow pockmark on the seafloor. Thereafter, a free gas pathway is formed below the pockmarks and the reservoir gas drains quickly. The pockmark depth is a function of thickness of free gas column beneath the hydrate and depth of the hydrate seal (bottom of hydrate layer). Interestingly, pockmark depth does not depend on sediment permeability. Pockmark depth implies the resource amount of free gas beneath hydrate layer. The model shows that a 22-m-thick free gas layer at least is needed to form a 4-m-deep pockmark on the rise of Blake Ridge.
文章类型	Article
关键词	Gas Hydrate Capillary Seal Gas Seepage Pockmarks Blake Ridge
WOS标题词	Science & Technology ; Physical Sciences
DOI	10.3969/j.issn.0001-5733.2009.12.022
研究领域[WOS]	Geochemistry & Geophysics
关键词[WOS]	LOWER CONGO BASIN ; FLUID-FLOW ; SEA ; POCKMARKS ; CONSTRAINTS
收录类别	SCI
语种	英语
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000273364200022
引用统计	被引频次：4[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.giec.ac.cn/handle/344007/10300
专题	中国科学院广州能源研究所
作者单位	1.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Key Lab Marginal Sea Geol, Guangzhou 510640, Peoples R China 2.Cornell Univ, Dept Earth & Atmospher Sci, Ithaca, NY 14853 USA 3.Chinese Acad Sci, Guangzhou Inst Energy Convers, CAS Key Lab Renewable Energy & Gas Hydrate, CAS Guangzhou Ctr Gas Hydrate Res, Guangzhou 510640, Peoples R China
第一作者单位	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	Su Zheng,Cao Yun-Cheng,Wu Neng-You,et al. Numerical computation and case analysis of the venting process of free gas beneath hydrate layer[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2009,52(12):3124-3131.
APA	Su Zheng,Cao Yun-Cheng,Wu Neng-You,Cathles, Lawrence M.,&Chen Duo-Fu.(2009).Numerical computation and case analysis of the venting process of free gas beneath hydrate layer.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,52(12),3124-3131.
MLA	Su Zheng,et al."Numerical computation and case analysis of the venting process of free gas beneath hydrate layer".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 52.12(2009):3124-3131.