Abstract:
Permafrost regions of Qilian Mountains in China are rich in gas hydrate resources.Once greenhouse gases in deep frozen layer are released into the atmosphere during hydrate mining,a series of negative consequences occur.This study aims to evaluate the impact of hydrate thermal exploitation on regional permafrost and carbon budgets based on a multi-physical field coupling simulation.The re-sults indicate that the permeability of the frozen soil is anisotropic,and the low permeability frozen lay-er can seal the methane gas in the natural state.Heat injection mining of hydrates causes the continuous melting of permafrost and the escape of methane gas,which transforms the regional permafrost from a carbon sink to a carbon source.A higher injection temperature concentrates the heat and causes uneven melting of the upper frozen layer,which provides a dominant channel for methane gas and results in in-creased methane emissions.However,dense heat injection wells cause more uniform melting of the low-er permafrost layer,and the melting zone does not extend to the upper low permeability formation,which cannot provide advantageous channels for methane gas.Therefore,a reasonable and dense num-ber of heat injection wells can reduce the risk of greenhouse gas emissions during hydrate exploitation.
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地球科学学刊(英文版)
ISSN: 1674-487X
Year: 2024
Issue: 6
Volume: 35
Page: 1934-1943
3 . 3 0 0
JCR@2022
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ESI Highly Cited Papers on the List: 0 Unfold All
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30 Days PV: 6
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