EFFECTS OF HEAT TRANSITION ON HYDRATE ACCUMULATION IN GAS VENT SITES
Received date: 2007-08-31
Revised date: 2007-10-31
Online published: 2008-06-20
Gas hydrate crystallization dissolution are exothermic/endothermic reactions, and gas venting from higher temperatures to the lower produces capacity heat, which results in the change bottom water temperature and consequently affects gas hydrate accumulation. We use the compositional kinetic model to analyze how hydrate latent heat and water capacity heat affect the gas hydrate stability in the Bush Hill. We take filter loss of venting gas as 1.8kg/(m 2·a) and there is 10% vent gas deposited as gas hydrate in the subsurface. Modeling shows that gas hydrate latent heat and water capacity heat within 10ka can perturb the temperature field in the subsurface of the Bush Hill, and thermal gradient increases 3 ℃/km at the surface of the seafloor and decreases ~1.4 ℃/km at 1km deep. The most obvious temperature variation, which is about 0.4℃,occurs in the middle part of the gas hydrate stability zone(400 mbsf deep), resulting in the reduction of hydrate stability zone by 12m and the dissolution of 0.06kg/m 2 of gas hydrate.
CAO Yuncheng,;CHEN Duofu, ;XU Wenyue . EFFECTS OF HEAT TRANSITION ON HYDRATE ACCUMULATION IN GAS VENT SITES[J]. Natural Gas Geoscience, 2007 , 18(6) : 827 -831 . DOI: 10.11764/j.issn.1672-1926.2007.06.827
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