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Indexed by:期刊论文

Date of Publication:2015-01-15

Journal:FUEL

Included Journals:SCIE

Volume:140

Page Number:126-135

ISSN No.:0016-2361

Key Words:Methane hydrate; Kinetics; Carbon dioxide sequestration; CH4-CO2 replacement; MRI

Abstract:The sequestration of CO2 in natural gas hydrate reservoirs is an attractive idea for both yielding CH4 and reducing CO(2)emissions. To investigate the kinetics of CO2-CH4 gas mixture hydrate formation and dissociation, two types of CO2-CH4 gas mixtures were applied to form hydrates in porous media with different porosities. The process of hydrate formation and dissociation was monitored in situ by magnetic resonance imaging (MRI) in this study. Hydrate saturation was calculated quantitatively using the mean intensity (MI) of each image. The results showed that the hydrates first formed in the centre of the porous media and then grew along the axis of the vessel. The hydrate saturation and the initial water saturation were linearly correlated when the initial water saturation changed from 5% to 40%. By comparing the formation process of two different CO2-CH4 gas mixtures, the formation rate of the 79.8% CO2/20.2% CH4 gas mixture hydrate was faster. The MRI data gave excellent information on the spatial distribution of water in the porous media during hydrate growth and dissociation. (C) 2014 Elsevier Ltd. All rights reserved.