气候变化领域集成服务门户(CCPortal): High concentration methane hydrate in a silt reservoir from the deep-water Gulf of Mexico

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DOI	10.1306/01062018280
	High concentration methane hydrate in a silt reservoir from the deep-water Gulf of Mexico
	Phillips S.C.; Flemings P.B.; Holland M.E.; Schultheiss P.J.; Waite W.F.; Jang J.; Petrou E.G.; Hammon H.
发表日期	2020
ISSN	0149-1423
起始页码	1971
结束页码	1995
卷号	104 期号:9
英文摘要	We present results from 30 quantitative degassing experiments of pressure core sections collected during The University of Texas-Gulf of Mexico 2-1 (UT-GOM2-1) Hydrate Pressure Coring Expedition at Green Canyon Block 955 in the deep-water Gulf of Mexico as part of The University of Texas at Austin-US Department of Energy Deepwater Methane Hydrate Characterization and Scientific Assessment. The hydrate saturation (Sh), the volume fraction of the pore space occupied by hydrate, is 79% to 93% within sandy silt beds (centimeters to meters in thickness) between 413 and 442 m below seafloor in 2032 m water depth. Sandy silt intervals are characterized by high compressional wave velocity (Vp) (2515-3012 m s-1) and are interbedded with clayey silt sections that have lower Sh (2%-35%) and lower Vp (1684-2023 m s-1). Clayey silt intervals are composed of thin laminae of silts with high Sh within clay-rich intervals containing little to no hydrate. Degassing of single-lithofacies sections reveals higher-resolution variation in Sh than is possible to observe in well logs; however, the average Sh of 64% through the reservoir is similar to well log estimates. Gas recovered from the hydrates during these experiments is composed almost entirely of methane (99.99% CH4, <100 ppm C2H6 on average), with an isotopic composition (d13C: -60.4% and -63.6% Vienna Peedee belemnite and d2H: -178.2% and -179.0% Vienna standard mean ocean water) that suggests the methane is primarily from a microbial source. A subset of six degassing experiments performed using very small pressure decrements indicates that the salinity within these samples is close to the average seawater concentration, suggesting that hydrate either formed slowly or formed during a rapid event at least tens of thousands of years before present. Copyright ©2020. The American Association of Petroleum Geologists. All rights reserved.
英文关键词	Degassing; Hydration; Methane; Silt; Wave propagation; Well logging; Compressional wave velocity; Higher resolution; Hydrate saturation; Isotopic composition; Seawater concentration; Standard mean ocean waters; University of Texas; US Department of Energy; Gas hydrates; concentration (composition); deep water; gas hydrate; isotopic composition; methane; pore space; reservoir characterization; seafloor; seawater; silt; standard (reference); well logging; Atlantic Ocean; Austin [Texas]; Green Canyon; Gulf of Mexico; Texas; United States; Belemnoidea; Lamiinae
语种	英语
来源期刊	AAPG Bulletin
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/168699
作者单位	Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, United States; Institute for Geophysics, Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, United States; Geotek, Ltd., Daventry, United Kingdom; US Geological Survey, Woods Hole, MA, United States; Integrated Statistics, Inc., Woods Hole, MA, United States
推荐引用方式 GB/T 7714	Phillips S.C.,Flemings P.B.,Holland M.E.,et al. High concentration methane hydrate in a silt reservoir from the deep-water Gulf of Mexico[J],2020,104(9).
APA	Phillips S.C..,Flemings P.B..,Holland M.E..,Schultheiss P.J..,Waite W.F..,...&Hammon H..(2020).High concentration methane hydrate in a silt reservoir from the deep-water Gulf of Mexico.AAPG Bulletin,104(9).
MLA	Phillips S.C.,et al."High concentration methane hydrate in a silt reservoir from the deep-water Gulf of Mexico".AAPG Bulletin 104.9(2020).