Structure II gas hydrates found below the bottom‐simulating reflector

Abstract Gas hydrates are a major component in the organic carbon cycle. Their stability is controlled by temperature, pressure, water chemistry, and gas composition. The bottom‐simulating reflector (BSR) is the primary seismic indicator of the base of hydrate stability in continental margins. Here...

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Main Authors: M. Paganoni, J. A. Cartwright, M. Foschi, R. C. Shipp, P. Van Rensbergen
Format: Article
Language:English
Published: Wiley 2016-06-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1002/2016GL069452
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author M. Paganoni
J. A. Cartwright
M. Foschi
R. C. Shipp
P. Van Rensbergen
author_facet M. Paganoni
J. A. Cartwright
M. Foschi
R. C. Shipp
P. Van Rensbergen
author_sort M. Paganoni
collection DOAJ
description Abstract Gas hydrates are a major component in the organic carbon cycle. Their stability is controlled by temperature, pressure, water chemistry, and gas composition. The bottom‐simulating reflector (BSR) is the primary seismic indicator of the base of hydrate stability in continental margins. Here we use seismic, well log, and core data from the convergent margin offshore NW Borneo to demonstrate that the BSR does not always represent the base of hydrate stability and can instead approximate the boundary between structure I hydrates above and structure II hydrates below. At this location, gas hydrate saturation below the BSR is higher than above and a process of chemical fractionation of the migrating free gas is responsible for the structure I‐II transition. This research shows that in geological settings dominated by thermogenic gas migration, the hydrate stability zone may extend much deeper than suggested by the BSR.
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institution OA Journals
issn 0094-8276
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publishDate 2016-06-01
publisher Wiley
record_format Article
series Geophysical Research Letters
spelling doaj-art-4c0f3663cd5f45cabbdac91ac4d12a792025-08-20T02:31:41ZengWileyGeophysical Research Letters0094-82761944-80072016-06-0143115696570610.1002/2016GL069452Structure II gas hydrates found below the bottom‐simulating reflectorM. Paganoni0J. A. Cartwright1M. Foschi2R. C. Shipp3P. Van Rensbergen4Department of Earth Sciences University of Oxford Oxford UKDepartment of Earth Sciences University of Oxford Oxford UKDepartment of Earth Sciences University of Oxford Oxford UKShell Exploration and Production Inc. Houston Texas USAShell International Global Solutions B.V. Rijswijk NetherlandsAbstract Gas hydrates are a major component in the organic carbon cycle. Their stability is controlled by temperature, pressure, water chemistry, and gas composition. The bottom‐simulating reflector (BSR) is the primary seismic indicator of the base of hydrate stability in continental margins. Here we use seismic, well log, and core data from the convergent margin offshore NW Borneo to demonstrate that the BSR does not always represent the base of hydrate stability and can instead approximate the boundary between structure I hydrates above and structure II hydrates below. At this location, gas hydrate saturation below the BSR is higher than above and a process of chemical fractionation of the migrating free gas is responsible for the structure I‐II transition. This research shows that in geological settings dominated by thermogenic gas migration, the hydrate stability zone may extend much deeper than suggested by the BSR.https://doi.org/10.1002/2016GL069452gas hydratesBSRhydrocarbon migrationthermogenic gashydrate stabilitychemical fractionation
spellingShingle M. Paganoni
J. A. Cartwright
M. Foschi
R. C. Shipp
P. Van Rensbergen
Structure II gas hydrates found below the bottom‐simulating reflector
Geophysical Research Letters
gas hydrates
BSR
hydrocarbon migration
thermogenic gas
hydrate stability
chemical fractionation
title Structure II gas hydrates found below the bottom‐simulating reflector
title_full Structure II gas hydrates found below the bottom‐simulating reflector
title_fullStr Structure II gas hydrates found below the bottom‐simulating reflector
title_full_unstemmed Structure II gas hydrates found below the bottom‐simulating reflector
title_short Structure II gas hydrates found below the bottom‐simulating reflector
title_sort structure ii gas hydrates found below the bottom simulating reflector
topic gas hydrates
BSR
hydrocarbon migration
thermogenic gas
hydrate stability
chemical fractionation
url https://doi.org/10.1002/2016GL069452
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