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The ‘excess gas’ method for laboratory formation of methane hydrate-bearing sand: geotechnical application
Over recent years, there has been a growing interest in producing methane gas from hydrate-bearing sands (MHBS) located below the permafrost in arctic regions and offshore within continental margins. Geotechnical stability of production wellbores is one of the significant challenges during the gas e...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8586339/ https://www.ncbi.nlm.nih.gov/pubmed/34764309 http://dx.doi.org/10.1038/s41598-021-00777-7 |
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author | Rake, Lior Pinkert, Shmulik |
author_facet | Rake, Lior Pinkert, Shmulik |
author_sort | Rake, Lior |
collection | PubMed |
description | Over recent years, there has been a growing interest in producing methane gas from hydrate-bearing sands (MHBS) located below the permafrost in arctic regions and offshore within continental margins. Geotechnical stability of production wellbores is one of the significant challenges during the gas extraction process. The vast majority of geotechnical investigations of MHBS have been conducted on laboratory-formed samples due to the complex procedure of undisturbed sample extraction. One of the most commonly used hydrate laboratory-formation methods is the excess-gas method. This work investigates fundamental aspects in the excess-gas formation of MHBS that are affecting the geotechnical interpretation and modeling. The work finds that (1) the measured temperature in the experimental system may be quite different from the in-sample temperature, and can reach 4 [Formula: see text] C difference during thermodynamic processes. This potential difference must be considered in investigation of hydrate formation or dissociation, (2) various calculation approaches may yield different hydrate saturation values of up to tens of percentages difference in high hydrate saturations. The calculation formulas are specified together with the fundamental difference between them, (3) the water mixture method during the sample assembling is critical for homogeneous MHBS laboratory formation, in which a maximum initial water content threshold of 9.1 to 1.3 % are obtained for a minimal fraction size of 0.01 to 0.8 mm, respectively, (4) the hydrate formation duration may influence the MHBS properties, and should be rigorously estimated according to the real-time gas consumption convergence. The outcomes of this work may contribute to the integration of data sets derived from various experiments for the study of MHBS mechanical behavior. |
format | Online Article Text |
id | pubmed-8586339 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-85863392021-11-16 The ‘excess gas’ method for laboratory formation of methane hydrate-bearing sand: geotechnical application Rake, Lior Pinkert, Shmulik Sci Rep Article Over recent years, there has been a growing interest in producing methane gas from hydrate-bearing sands (MHBS) located below the permafrost in arctic regions and offshore within continental margins. Geotechnical stability of production wellbores is one of the significant challenges during the gas extraction process. The vast majority of geotechnical investigations of MHBS have been conducted on laboratory-formed samples due to the complex procedure of undisturbed sample extraction. One of the most commonly used hydrate laboratory-formation methods is the excess-gas method. This work investigates fundamental aspects in the excess-gas formation of MHBS that are affecting the geotechnical interpretation and modeling. The work finds that (1) the measured temperature in the experimental system may be quite different from the in-sample temperature, and can reach 4 [Formula: see text] C difference during thermodynamic processes. This potential difference must be considered in investigation of hydrate formation or dissociation, (2) various calculation approaches may yield different hydrate saturation values of up to tens of percentages difference in high hydrate saturations. The calculation formulas are specified together with the fundamental difference between them, (3) the water mixture method during the sample assembling is critical for homogeneous MHBS laboratory formation, in which a maximum initial water content threshold of 9.1 to 1.3 % are obtained for a minimal fraction size of 0.01 to 0.8 mm, respectively, (4) the hydrate formation duration may influence the MHBS properties, and should be rigorously estimated according to the real-time gas consumption convergence. The outcomes of this work may contribute to the integration of data sets derived from various experiments for the study of MHBS mechanical behavior. Nature Publishing Group UK 2021-11-11 /pmc/articles/PMC8586339/ /pubmed/34764309 http://dx.doi.org/10.1038/s41598-021-00777-7 Text en © The Author(s) 2021 https://creativecommons.org/licenses/by/4.0/Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Article Rake, Lior Pinkert, Shmulik The ‘excess gas’ method for laboratory formation of methane hydrate-bearing sand: geotechnical application |
title | The ‘excess gas’ method for laboratory formation of methane hydrate-bearing sand: geotechnical application |
title_full | The ‘excess gas’ method for laboratory formation of methane hydrate-bearing sand: geotechnical application |
title_fullStr | The ‘excess gas’ method for laboratory formation of methane hydrate-bearing sand: geotechnical application |
title_full_unstemmed | The ‘excess gas’ method for laboratory formation of methane hydrate-bearing sand: geotechnical application |
title_short | The ‘excess gas’ method for laboratory formation of methane hydrate-bearing sand: geotechnical application |
title_sort | ‘excess gas’ method for laboratory formation of methane hydrate-bearing sand: geotechnical application |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8586339/ https://www.ncbi.nlm.nih.gov/pubmed/34764309 http://dx.doi.org/10.1038/s41598-021-00777-7 |
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