Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production
In this simulation study, we analyzed the geomechanical response during depressurization production from two known hydrate-bearing permafrost deposits: the Mallik (Northwest Territories, Canada) deposit and Mount Elbert (Alaska, USA) deposit. Gas was produced from these deposits at constant pressure...
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Lawrence Berkeley National Laboratory
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ftunivnotexas:info:ark/67531/metadc932396 2023-05-15T17:46:45+02:00 Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production Rutqvist, J. Moridis, G.J. Grover, T. Collett, T. Lawrence Berkeley National Laboratory. Earth Sciences Division. 2009-02-01 Text https://doi.org/10.1016/j.petrol.2009.02.013 https://digital.library.unt.edu/ark:/67531/metadc932396/ English eng Lawrence Berkeley National Laboratory rep-no: LBNL-1614E grantno: DE-AC02-05CH11231 doi:10.1016/j.petrol.2009.02.013 osti: 953689 https://digital.library.unt.edu/ark:/67531/metadc932396/ ark: ark:/67531/metadc932396 Journal Name: Journal of Petroleum Science and Engineering; Related Information: Journal Publication Date: 2009 Canada 58 Sediments Layers 54 Zones Deposits Hydrates Simulation Wells Thermodynamics Depth Production Failures Stresses Overburden Depressurization Dissociation Permafrost Shear Alaska Article 2009 ftunivnotexas https://doi.org/10.1016/j.petrol.2009.02.013 2017-09-30T22:08:02Z In this simulation study, we analyzed the geomechanical response during depressurization production from two known hydrate-bearing permafrost deposits: the Mallik (Northwest Territories, Canada) deposit and Mount Elbert (Alaska, USA) deposit. Gas was produced from these deposits at constant pressure using horizontal wells placed at the top of a hydrate layer (HL), located at a depth of about 900 m at the Mallik and 600 m at the Mount Elbert. The simulation results show that general thermodynamic and geomechanical responses are similar for the two sites, but with substantially higher production and more intensive geomechanical responses at the deeper Mallik deposit. The depressurization-induced dissociation begins at the well bore and then spreads laterally, mainly along the top of the HL. The depressurization results in an increased shear stress within the body of the receding hydrate and causes a vertical compaction of the reservoir. However, its effects are partially mitigated by the relatively stiff permafrost overburden, and compaction of the HL is limited to less than 0.4%. The increased shear stress may lead to shear failure in the hydrate-free zone bounded by the HL overburden and the downward-receding upper dissociation interface. This zone undergoes complete hydrate dissociation, and the cohesive strength of the sediment is low. We determined that the likelihood of shear failure depends on the initial stress state as well as on the geomechanical properties of the reservoir. The Poisson's ratio of the hydrate-bearing formation is a particularly important parameter that determines whether the evolution of the reservoir stresses will increase or decrease the likelihood of shear failure. Article in Journal/Newspaper Northwest Territories permafrost Alaska University of North Texas: UNT Digital Library Canada Northwest Territories Journal of Petroleum Science and Engineering 67 1-2 1 12 |
institution |
Open Polar |
collection |
University of North Texas: UNT Digital Library |
op_collection_id |
ftunivnotexas |
language |
English |
topic |
Canada 58 Sediments Layers 54 Zones Deposits Hydrates Simulation Wells Thermodynamics Depth Production Failures Stresses Overburden Depressurization Dissociation Permafrost Shear Alaska |
spellingShingle |
Canada 58 Sediments Layers 54 Zones Deposits Hydrates Simulation Wells Thermodynamics Depth Production Failures Stresses Overburden Depressurization Dissociation Permafrost Shear Alaska Rutqvist, J. Moridis, G.J. Grover, T. Collett, T. Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production |
topic_facet |
Canada 58 Sediments Layers 54 Zones Deposits Hydrates Simulation Wells Thermodynamics Depth Production Failures Stresses Overburden Depressurization Dissociation Permafrost Shear Alaska |
description |
In this simulation study, we analyzed the geomechanical response during depressurization production from two known hydrate-bearing permafrost deposits: the Mallik (Northwest Territories, Canada) deposit and Mount Elbert (Alaska, USA) deposit. Gas was produced from these deposits at constant pressure using horizontal wells placed at the top of a hydrate layer (HL), located at a depth of about 900 m at the Mallik and 600 m at the Mount Elbert. The simulation results show that general thermodynamic and geomechanical responses are similar for the two sites, but with substantially higher production and more intensive geomechanical responses at the deeper Mallik deposit. The depressurization-induced dissociation begins at the well bore and then spreads laterally, mainly along the top of the HL. The depressurization results in an increased shear stress within the body of the receding hydrate and causes a vertical compaction of the reservoir. However, its effects are partially mitigated by the relatively stiff permafrost overburden, and compaction of the HL is limited to less than 0.4%. The increased shear stress may lead to shear failure in the hydrate-free zone bounded by the HL overburden and the downward-receding upper dissociation interface. This zone undergoes complete hydrate dissociation, and the cohesive strength of the sediment is low. We determined that the likelihood of shear failure depends on the initial stress state as well as on the geomechanical properties of the reservoir. The Poisson's ratio of the hydrate-bearing formation is a particularly important parameter that determines whether the evolution of the reservoir stresses will increase or decrease the likelihood of shear failure. |
author2 |
Lawrence Berkeley National Laboratory. Earth Sciences Division. |
format |
Article in Journal/Newspaper |
author |
Rutqvist, J. Moridis, G.J. Grover, T. Collett, T. |
author_facet |
Rutqvist, J. Moridis, G.J. Grover, T. Collett, T. |
author_sort |
Rutqvist, J. |
title |
Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production |
title_short |
Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production |
title_full |
Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production |
title_fullStr |
Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production |
title_full_unstemmed |
Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production |
title_sort |
geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production |
publisher |
Lawrence Berkeley National Laboratory |
publishDate |
2009 |
url |
https://doi.org/10.1016/j.petrol.2009.02.013 https://digital.library.unt.edu/ark:/67531/metadc932396/ |
geographic |
Canada Northwest Territories |
geographic_facet |
Canada Northwest Territories |
genre |
Northwest Territories permafrost Alaska |
genre_facet |
Northwest Territories permafrost Alaska |
op_source |
Journal Name: Journal of Petroleum Science and Engineering; Related Information: Journal Publication Date: 2009 |
op_relation |
rep-no: LBNL-1614E grantno: DE-AC02-05CH11231 doi:10.1016/j.petrol.2009.02.013 osti: 953689 https://digital.library.unt.edu/ark:/67531/metadc932396/ ark: ark:/67531/metadc932396 |
op_doi |
https://doi.org/10.1016/j.petrol.2009.02.013 |
container_title |
Journal of Petroleum Science and Engineering |
container_volume |
67 |
container_issue |
1-2 |
container_start_page |
1 |
op_container_end_page |
12 |
_version_ |
1766150593047429120 |