Dynamics of gas flow and hydrate formation within the hydrate stability zone
Methane hydrate comprises a significant piece of the global carbon cycle and is an important potential energy resource. Thick marine sands around the world contain free gas beneath and high concentrations of methane hydrate far above the base of the hydrate stability zone. The mechanisms controlling...
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ftunivtexas:oai:repositories.lib.utexas.edu:2152/68934 2023-05-15T17:11:51+02:00 Dynamics of gas flow and hydrate formation within the hydrate stability zone Meyer, Dylan Whitney Flemings, Peter Barry, 1960- DiCarlo, David Kneafsey, Timothy J Gulick, Sean S Ketcham, Richard A 2018-08 application/pdf http://hdl.handle.net/2152/68934 https://doi.org/10.15781/T2M03ZG8H en eng doi:10.15781/T2M03ZG8H http://hdl.handle.net/2152/68934 Methane hydrate Gas transport Computed-tomography Thesis text 2018 ftunivtexas https://doi.org/10.15781/T2M03ZG8H 2020-12-23T22:13:37Z Methane hydrate comprises a significant piece of the global carbon cycle and is an important potential energy resource. Thick marine sands around the world contain free gas beneath and high concentrations of methane hydrate far above the base of the hydrate stability zone. The mechanisms controlling gas transport and hydrate formation within the region where hydrate is stable remains an important research question. I developed a new experimental method to investigate the fundamental behaviors associated with hydrate formation during gas flow into the hydrate stability zone. First, I performed a set of experiments at the same experimental conditions, to determine the repeatability of this behavior. I compared these results to those from an experiment performed outside the hydrate stability zone to elucidate the change in intrinsic gas flow behavior due to hydrate formation. Second, I performed additional experiments at a range of flow rates as well as several shut-in experiments, where I observed long-term hydrate formation after flow took place. I analyzed the bulk and core-scale behaviors of these experiments using a combination of mass balance and computed-tomography analyses. I found that many of my experimentally observed behaviors are not accurately described by previous models and that the mechanism for gas transport was fundamentally different than typically assumed. I proposed that hydrate formation at the gas-brine interface separates the gas and brine phases and limits hydrate formation to methane transport through the hydrate. This behavior produced temporary flow blockages that were mitigated when the hydrate skin fails due to pressure gradients across the sample. This behavior also produced different thermodynamics states on either side of the hydrate that could persist for hundreds to thousands of years. These results provide an alternative mechanism for gas transport and hydrate formation through the hydrate stability zone that does not require the gas, hydrate, and brine to be at three-phase equilibrium. This mechanism provides a first-order connection between experimentally observed micro-scale phenomena and field-scale gas transport and hydrate formation behaviors in these reservoirs. Geological Sciences Thesis Methane hydrate The University of Texas at Austin: Texas ScholarWorks |
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The University of Texas at Austin: Texas ScholarWorks |
op_collection_id |
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language |
English |
topic |
Methane hydrate Gas transport Computed-tomography |
spellingShingle |
Methane hydrate Gas transport Computed-tomography Meyer, Dylan Whitney Dynamics of gas flow and hydrate formation within the hydrate stability zone |
topic_facet |
Methane hydrate Gas transport Computed-tomography |
description |
Methane hydrate comprises a significant piece of the global carbon cycle and is an important potential energy resource. Thick marine sands around the world contain free gas beneath and high concentrations of methane hydrate far above the base of the hydrate stability zone. The mechanisms controlling gas transport and hydrate formation within the region where hydrate is stable remains an important research question. I developed a new experimental method to investigate the fundamental behaviors associated with hydrate formation during gas flow into the hydrate stability zone. First, I performed a set of experiments at the same experimental conditions, to determine the repeatability of this behavior. I compared these results to those from an experiment performed outside the hydrate stability zone to elucidate the change in intrinsic gas flow behavior due to hydrate formation. Second, I performed additional experiments at a range of flow rates as well as several shut-in experiments, where I observed long-term hydrate formation after flow took place. I analyzed the bulk and core-scale behaviors of these experiments using a combination of mass balance and computed-tomography analyses. I found that many of my experimentally observed behaviors are not accurately described by previous models and that the mechanism for gas transport was fundamentally different than typically assumed. I proposed that hydrate formation at the gas-brine interface separates the gas and brine phases and limits hydrate formation to methane transport through the hydrate. This behavior produced temporary flow blockages that were mitigated when the hydrate skin fails due to pressure gradients across the sample. This behavior also produced different thermodynamics states on either side of the hydrate that could persist for hundreds to thousands of years. These results provide an alternative mechanism for gas transport and hydrate formation through the hydrate stability zone that does not require the gas, hydrate, and brine to be at three-phase equilibrium. This mechanism provides a first-order connection between experimentally observed micro-scale phenomena and field-scale gas transport and hydrate formation behaviors in these reservoirs. Geological Sciences |
author2 |
Flemings, Peter Barry, 1960- DiCarlo, David Kneafsey, Timothy J Gulick, Sean S Ketcham, Richard A |
format |
Thesis |
author |
Meyer, Dylan Whitney |
author_facet |
Meyer, Dylan Whitney |
author_sort |
Meyer, Dylan Whitney |
title |
Dynamics of gas flow and hydrate formation within the hydrate stability zone |
title_short |
Dynamics of gas flow and hydrate formation within the hydrate stability zone |
title_full |
Dynamics of gas flow and hydrate formation within the hydrate stability zone |
title_fullStr |
Dynamics of gas flow and hydrate formation within the hydrate stability zone |
title_full_unstemmed |
Dynamics of gas flow and hydrate formation within the hydrate stability zone |
title_sort |
dynamics of gas flow and hydrate formation within the hydrate stability zone |
publishDate |
2018 |
url |
http://hdl.handle.net/2152/68934 https://doi.org/10.15781/T2M03ZG8H |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_relation |
doi:10.15781/T2M03ZG8H http://hdl.handle.net/2152/68934 |
op_doi |
https://doi.org/10.15781/T2M03ZG8H |
_version_ |
1766068612331732992 |