Hydrate Formation and CH4 Production from Natural Gas Hydrates - Emphasis on Boundary Conditions and Production Methods
Natural gas hydrate is a solid state of gas and water at low temperature and high pressure. Gas hydrates are known to form hydrate plugs in production line, and has thus generally been considered a problem to the oil industry. However, the energy stored in gas hydrates is vast, and as the global ene...
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The University of Bergen
2009
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ftunivbergen:oai:bora.uib.no:1956/3425 2023-05-15T17:58:21+02:00 Hydrate Formation and CH4 Production from Natural Gas Hydrates - Emphasis on Boundary Conditions and Production Methods Birkedal, Knut Arne 2009-05-13 2468775 bytes application/pdf https://hdl.handle.net/1956/3425 eng eng The University of Bergen https://hdl.handle.net/1956/3425 The author Copyright the author. All rights reserved Gas Hydrates Production Salinity Methane Depressurization CO2 Sequestration 759906 VDP::Matematikk og Naturvitenskap: 400::Fysikk: 430 Master thesis 2009 ftunivbergen 2023-03-14T17:43:32Z Natural gas hydrate is a solid state of gas and water at low temperature and high pressure. Gas hydrates are known to form hydrate plugs in production line, and has thus generally been considered a problem to the oil industry. However, the energy stored in gas hydrates is vast, and as the global energy demand increases, focus is shifted on gas hydrates as a potential energy resource. The work presented in this thesis is a series of experimental studies of hydrate formation and dissociation kinetics in porous sandstone. The overall objective was to provide an improved basic understanding of processes involved with formation and production of methane (CH4) gas hydrates within porous media and to obtain data for numerical modelling and scaling. CH4 hydrate has been formed repeatedly in Bentheim sandstone rocks to study hydrate formation patterns as function of initial water and gas saturations and salinity, and to prepare for subsequent lab-scale gas production tests using two different production schemes: 1) CH4 production by carbon dioxide replacement, and 2) CH4 production by dissociation of hydrates through depressurization. Salinity impacts on induction time and hydrate growth pattern has been investigated through six different experiments, looking at the effect of salinities ranging between 1 wt% and 10 wt%. Salts are well known hydrate inhibitors and may affect both induction time for nucleation and hydrate growth pattern. These results show that salinities below 4 wt% NaCl do not seem to affect the hydrate formation rate significantly. However, at higher salinities (4.5-10 wt% NaCl) the inhibition is evident. The results show a reduction of the amount of water converted to gas hydrates and an increase in induction time with increasing salinity. Depressurization is by many considered the most promising production method, and is the only successful production method to date on field scale (The Messoyaka field located in the eastern Siberian permafrost). This production method is based on dissociation of gas ... Master Thesis permafrost University of Bergen: Bergen Open Research Archive (BORA-UiB) |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
Gas Hydrates Production Salinity Methane Depressurization CO2 Sequestration 759906 VDP::Matematikk og Naturvitenskap: 400::Fysikk: 430 |
spellingShingle |
Gas Hydrates Production Salinity Methane Depressurization CO2 Sequestration 759906 VDP::Matematikk og Naturvitenskap: 400::Fysikk: 430 Birkedal, Knut Arne Hydrate Formation and CH4 Production from Natural Gas Hydrates - Emphasis on Boundary Conditions and Production Methods |
topic_facet |
Gas Hydrates Production Salinity Methane Depressurization CO2 Sequestration 759906 VDP::Matematikk og Naturvitenskap: 400::Fysikk: 430 |
description |
Natural gas hydrate is a solid state of gas and water at low temperature and high pressure. Gas hydrates are known to form hydrate plugs in production line, and has thus generally been considered a problem to the oil industry. However, the energy stored in gas hydrates is vast, and as the global energy demand increases, focus is shifted on gas hydrates as a potential energy resource. The work presented in this thesis is a series of experimental studies of hydrate formation and dissociation kinetics in porous sandstone. The overall objective was to provide an improved basic understanding of processes involved with formation and production of methane (CH4) gas hydrates within porous media and to obtain data for numerical modelling and scaling. CH4 hydrate has been formed repeatedly in Bentheim sandstone rocks to study hydrate formation patterns as function of initial water and gas saturations and salinity, and to prepare for subsequent lab-scale gas production tests using two different production schemes: 1) CH4 production by carbon dioxide replacement, and 2) CH4 production by dissociation of hydrates through depressurization. Salinity impacts on induction time and hydrate growth pattern has been investigated through six different experiments, looking at the effect of salinities ranging between 1 wt% and 10 wt%. Salts are well known hydrate inhibitors and may affect both induction time for nucleation and hydrate growth pattern. These results show that salinities below 4 wt% NaCl do not seem to affect the hydrate formation rate significantly. However, at higher salinities (4.5-10 wt% NaCl) the inhibition is evident. The results show a reduction of the amount of water converted to gas hydrates and an increase in induction time with increasing salinity. Depressurization is by many considered the most promising production method, and is the only successful production method to date on field scale (The Messoyaka field located in the eastern Siberian permafrost). This production method is based on dissociation of gas ... |
format |
Master Thesis |
author |
Birkedal, Knut Arne |
author_facet |
Birkedal, Knut Arne |
author_sort |
Birkedal, Knut Arne |
title |
Hydrate Formation and CH4 Production from Natural Gas Hydrates - Emphasis on Boundary Conditions and Production Methods |
title_short |
Hydrate Formation and CH4 Production from Natural Gas Hydrates - Emphasis on Boundary Conditions and Production Methods |
title_full |
Hydrate Formation and CH4 Production from Natural Gas Hydrates - Emphasis on Boundary Conditions and Production Methods |
title_fullStr |
Hydrate Formation and CH4 Production from Natural Gas Hydrates - Emphasis on Boundary Conditions and Production Methods |
title_full_unstemmed |
Hydrate Formation and CH4 Production from Natural Gas Hydrates - Emphasis on Boundary Conditions and Production Methods |
title_sort |
hydrate formation and ch4 production from natural gas hydrates - emphasis on boundary conditions and production methods |
publisher |
The University of Bergen |
publishDate |
2009 |
url |
https://hdl.handle.net/1956/3425 |
genre |
permafrost |
genre_facet |
permafrost |
op_relation |
https://hdl.handle.net/1956/3425 |
op_rights |
The author Copyright the author. All rights reserved |
_version_ |
1766166946472001536 |