The effect of heterogeneities in hydrate saturation on gas production from natural systems
The effect of heterogeneities in hydrate saturation on gas production from natural systems
Understanding the rate and time evolution of gas release from natural gas hydrate systems is important when evaluating the potential of gas hydrate as a future energy source, or the impact of gas from hydrate on climate. The release of gas from hydrate is heavily influenced by a number of factors, many of which vary through the hydrate system. The fundamental heterogeneity of natural gas hydrate systems is often poorly represented in models. Here we simulate depressurisation-induced gas production from a single vertical well in 34 models with heterogeneous 2D distributions of hydrate that include layered, columnar or random configurations and comparable models with homogenous saturation distributions. We found that the temporal evolution of gas production rate follows a consistent trend for all models, but at any time the gas production rate across the models varied by up to ±35% in the first year of production, and by up to ±25% thereafter. The primary control on the gas production rate is the overall amount of hydrate in the system, but local variations in hydrate saturation cause significant fluctuations in the time evolution of production. These hydrate variations can cause changes in the gas flow path through the system and associated drops in gas production rate continuing for multiple years. Overall, our results suggest that small levels of heterogeneity in hydrate systems can cause variations in the gas production rate similar in scale to much larger variations in homogenous systems. Our work provides an error margin for previously modelled gas production rates, and a note of caution for potential commercial development of gas hydrate.
Depressurisation, Gas production, Heterogeneity, Natural gas hydrate, Numerical simulation
Riley, David
f9649d09-cf4f-4b21-9ada-07d08294dad5
Marin-Moreno, Héctor
e466cafd-bd5c-47a1-8522-e6938e7086a4
Minshull, Tim A.
bf413fb5-849e-4389-acd7-0cb0d644e6b8
6 September 2019
Riley, David
f9649d09-cf4f-4b21-9ada-07d08294dad5
Marin-Moreno, Héctor
e466cafd-bd5c-47a1-8522-e6938e7086a4
Minshull, Tim A.
bf413fb5-849e-4389-acd7-0cb0d644e6b8
Riley, David, Marin-Moreno, Héctor and Minshull, Tim A.
(2019)
The effect of heterogeneities in hydrate saturation on gas production from natural systems.
Journal of Petroleum Science and Engineering, 183, [106452].
(doi:10.1016/j.petrol.2019.106452).
Abstract
Understanding the rate and time evolution of gas release from natural gas hydrate systems is important when evaluating the potential of gas hydrate as a future energy source, or the impact of gas from hydrate on climate. The release of gas from hydrate is heavily influenced by a number of factors, many of which vary through the hydrate system. The fundamental heterogeneity of natural gas hydrate systems is often poorly represented in models. Here we simulate depressurisation-induced gas production from a single vertical well in 34 models with heterogeneous 2D distributions of hydrate that include layered, columnar or random configurations and comparable models with homogenous saturation distributions. We found that the temporal evolution of gas production rate follows a consistent trend for all models, but at any time the gas production rate across the models varied by up to ±35% in the first year of production, and by up to ±25% thereafter. The primary control on the gas production rate is the overall amount of hydrate in the system, but local variations in hydrate saturation cause significant fluctuations in the time evolution of production. These hydrate variations can cause changes in the gas flow path through the system and associated drops in gas production rate continuing for multiple years. Overall, our results suggest that small levels of heterogeneity in hydrate systems can cause variations in the gas production rate similar in scale to much larger variations in homogenous systems. Our work provides an error margin for previously modelled gas production rates, and a note of caution for potential commercial development of gas hydrate.
Text
Effect of hydrate heterogeneities on gas production
- Accepted Manuscript
More information
Accepted/In Press date: 29 August 2019
e-pub ahead of print date: 29 August 2019
Published date: 6 September 2019
Additional Information:
Funding Information:
Funding source had no involvement in study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the article for publication. David Riley was supported by the University of Southampton , and a SMMI Leverhulme Trust Doctoral Scholarship. Tim Minshull was supported by a Wolfson Research Merit Award.
Keywords:
Depressurisation, Gas production, Heterogeneity, Natural gas hydrate, Numerical simulation
Identifiers
Local EPrints ID: 433980
URI: http://eprints.soton.ac.uk/id/eprint/433980
ISSN: 0920-4105
PURE UUID: ff242d99-b987-48b5-b3d4-7180d06025f3
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Date deposited: 09 Sep 2019 16:30
Last modified: 17 Mar 2024 02:50
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Author:
David Riley
Author:
Héctor Marin-Moreno
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