Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation
Collecting and preserving undamaged core samples containing gas hydrates from depth is difficult because of the pressure and temperature changes encountered upon retrieval. Hydrate-bearing core samples were collected at the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well in February 2...
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Lawrence Berkeley National Laboratory
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Online Access: | https://doi.org/10.1016/j.marpetgeo.2009.10.009 https://digital.library.unt.edu/ark:/67531/metadc843130/ |
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ftunivnotexas:info:ark/67531/metadc843130 2023-05-15T13:09:10+02:00 Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation Kneafsey, T.J. Liu, T.J. H. Winters, W. Boswell, R. Hunter, R. Collett, T.S. Lawrence Berkeley National Laboratory. Earth Sciences Division. 2011-06-01 381 Text https://doi.org/10.1016/j.marpetgeo.2009.10.009 https://digital.library.unt.edu/ark:/67531/metadc843130/ English eng Lawrence Berkeley National Laboratory rep-no: LBNL-5134E grantno: DE-AC02-05CH11231 doi:10.1016/j.marpetgeo.2009.10.009 osti: 1051633 https://digital.library.unt.edu/ark:/67531/metadc843130/ ark: ark:/67531/metadc843130 Journal Name: Marine and Petroleum Geology; Journal Volume: 28; Journal Issue: 2; Related Information: Journal Publication Date: 2011 54 Environmental Sciences 58 Geosciences Article 2011 ftunivnotexas https://doi.org/10.1016/j.marpetgeo.2009.10.009 2017-09-30T22:07:45Z Collecting and preserving undamaged core samples containing gas hydrates from depth is difficult because of the pressure and temperature changes encountered upon retrieval. Hydrate-bearing core samples were collected at the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well in February 2007. Coring was performed while using a custom oil-based drilling mud, and the cores were retrieved by a wireline. The samples were characterized and subsampled at the surface under ambient winter arctic conditions. Samples thought to be hydrate bearing were preserved either by immersion in liquid nitrogen (LN), or by storage under methane pressure at ambient arctic conditions, and later depressurized and immersed in LN. Eleven core samples from hydrate-bearing zones were scanned using x-ray computed tomography to examine core structure and homogeneity. Features observed include radial fractures, spalling-type fractures, and reduced density near the periphery. These features were induced during sample collection, handling, and preservation. Isotopic analysis of the methane from hydrate in an initially LN-preserved core and a pressure-preserved core indicate that secondary hydrate formation occurred throughout the pressurized core, whereas none occurred in the LN-preserved core, however no hydrate was found near the periphery of the LN-preserved core. To replicate some aspects of the preservation methods, natural and laboratory-made saturated porous media samples were frozen in a variety of ways, with radial fractures observed in some LN-frozen sands, and needle-like ice crystals forming in slowly frozen clay-rich sediments. Suggestions for hydrate-bearing core preservation are presented. Article in Journal/Newspaper Alaska North Slope Arctic north slope Alaska University of North Texas: UNT Digital Library Arctic Marine and Petroleum Geology 28 2 381 393 |
institution |
Open Polar |
collection |
University of North Texas: UNT Digital Library |
op_collection_id |
ftunivnotexas |
language |
English |
topic |
54 Environmental Sciences 58 Geosciences |
spellingShingle |
54 Environmental Sciences 58 Geosciences Kneafsey, T.J. Liu, T.J. H. Winters, W. Boswell, R. Hunter, R. Collett, T.S. Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation |
topic_facet |
54 Environmental Sciences 58 Geosciences |
description |
Collecting and preserving undamaged core samples containing gas hydrates from depth is difficult because of the pressure and temperature changes encountered upon retrieval. Hydrate-bearing core samples were collected at the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well in February 2007. Coring was performed while using a custom oil-based drilling mud, and the cores were retrieved by a wireline. The samples were characterized and subsampled at the surface under ambient winter arctic conditions. Samples thought to be hydrate bearing were preserved either by immersion in liquid nitrogen (LN), or by storage under methane pressure at ambient arctic conditions, and later depressurized and immersed in LN. Eleven core samples from hydrate-bearing zones were scanned using x-ray computed tomography to examine core structure and homogeneity. Features observed include radial fractures, spalling-type fractures, and reduced density near the periphery. These features were induced during sample collection, handling, and preservation. Isotopic analysis of the methane from hydrate in an initially LN-preserved core and a pressure-preserved core indicate that secondary hydrate formation occurred throughout the pressurized core, whereas none occurred in the LN-preserved core, however no hydrate was found near the periphery of the LN-preserved core. To replicate some aspects of the preservation methods, natural and laboratory-made saturated porous media samples were frozen in a variety of ways, with radial fractures observed in some LN-frozen sands, and needle-like ice crystals forming in slowly frozen clay-rich sediments. Suggestions for hydrate-bearing core preservation are presented. |
author2 |
Lawrence Berkeley National Laboratory. Earth Sciences Division. |
format |
Article in Journal/Newspaper |
author |
Kneafsey, T.J. Liu, T.J. H. Winters, W. Boswell, R. Hunter, R. Collett, T.S. |
author_facet |
Kneafsey, T.J. Liu, T.J. H. Winters, W. Boswell, R. Hunter, R. Collett, T.S. |
author_sort |
Kneafsey, T.J. |
title |
Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation |
title_short |
Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation |
title_full |
Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation |
title_fullStr |
Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation |
title_full_unstemmed |
Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation |
title_sort |
examination of core samples from the mount elbert gas hydrate stratigraphic test well, alaska north slope: effects of retrieval and preservation |
publisher |
Lawrence Berkeley National Laboratory |
publishDate |
2011 |
url |
https://doi.org/10.1016/j.marpetgeo.2009.10.009 https://digital.library.unt.edu/ark:/67531/metadc843130/ |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Alaska North Slope Arctic north slope Alaska |
genre_facet |
Alaska North Slope Arctic north slope Alaska |
op_source |
Journal Name: Marine and Petroleum Geology; Journal Volume: 28; Journal Issue: 2; Related Information: Journal Publication Date: 2011 |
op_relation |
rep-no: LBNL-5134E grantno: DE-AC02-05CH11231 doi:10.1016/j.marpetgeo.2009.10.009 osti: 1051633 https://digital.library.unt.edu/ark:/67531/metadc843130/ ark: ark:/67531/metadc843130 |
op_doi |
https://doi.org/10.1016/j.marpetgeo.2009.10.009 |
container_title |
Marine and Petroleum Geology |
container_volume |
28 |
container_issue |
2 |
container_start_page |
381 |
op_container_end_page |
393 |
_version_ |
1766165757042884608 |