Theoretical Analysis of Gas Hydrate Dissociation in Sediment
Theoretical analysis was carried out to investigate the dissociation of gas hydrate in stiff sediment. First the mathematical model for gas hydrate dissociation was decoupled by asymptotic expansion method considering the order differences of time scales among seepage, dissociation of gas hydrate and heat conduction. The multi-scale perturbation method was used to solve the problem. It is shown that seepage is the fastest process. The heat conduction is the slowest process. With the pressure decreases at the boundary, pressure changes first while no hydrate dissociation and heat conduction occur. Gradually, dissociation causes the decrease of temperature. After a long time, heat can conduct to cause the increase of temperature. Otherwise, the decreased temperature will cause the stop of dissociation if no heat is supplied in time.
KeywordsGas hydrate Dissociation Mathematical model
This project is supported by the Open Research Fund of Shanghai Key Laboratory of Mechanics in Energy Engineering and China natural Science Fund (No.11272314 and No.51239010).
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