Over het archief
Het OWA, het open archief van het Waterbouwkundig Laboratorium heeft tot doel alle vrij toegankelijke onderzoeksresultaten van dit instituut in digitale vorm aan te bieden. Op die manier wil het de zichtbaarheid, verspreiding en gebruik van deze onderzoeksresultaten, alsook de wetenschappelijke communicatie maximaal bevorderen.
Dit archief wordt uitgebouwd en beheerd volgens de principes van de Open Access Movement, en het daaruit ontstane Open Archives Initiative.
Basisinformatie over ‘Open Access to scholarly information'.
| one publication added to basket [367060] |
Long- and short-term dynamic stability of submarine slopes undergoing hydrate dissociation
Song, X.; Nian, T.; Mestdagh, T.; De Batist, M. (2023). Long- and short-term dynamic stability of submarine slopes undergoing hydrate dissociation. Gas Science and Engineering 111: 204934. https://dx.doi.org/10.1016/j.jgsce.2023.204934
In: Gas Science and Engineering. Elsevier: Netherlands. ISSN 2949-9097; e-ISSN 2949-9089, meer
|  |
| Trefwoord |
|
| Author keywords |
Marine gas hydrate dissociation; THC coupling Analysis; Dynamic stability; Slope failure pattern; Shenhu area |
| Abstract |
Natural gas hydrates (NGHs) have recently been recognized as a promising source of relatively clean alternative energy and a significant factor in triggering marine geohazards. This paper presents a numerical method for calculating the transient excess pore pressure associated with hydrate dissociation in submarine sediments with THC (Thermo-Hydro-Chemical) coupling. Then, the dynamic stability of submarine slopes experiencing gas hydrate dissociation is evaluated based on limit equilibrium analysis considering the real evolution of excess pore pressure. Finally, this work is applied to investigate the dynamic responses of typical hydrate slopes in the Shenhu Sea area, South China Sea (SCS), under two different timescales: 1) Case I: gradual temperature increases at the seafloor due to climate warming and 2) Case II: sharp temperature increases in the interior of the hydrate deposit due to hydrate extraction. In Case Ⅰ, the timescale of hydrate dissociation is millennial. Due to the long-term temperature rise, the hydrate will dissociate slowly, which allows the generated free gas to migrate upwards and gradually accumulate at the transition zone between a porous layer and an overlying low-permeability layer. Eventually, the slow accumulation of free gas may lead to disc-shaped failure of the hydrate-bearing slope. In contrast, in Case Ⅱ, the temperature rises sharply over a short period of time, which leads to the drastic dissociation of the hydrate. The timescale of hydrate dissociation is decadal. As a result, the excess pore pressure accumulates rapidly. Under the influence of excess pore pressure, the sediment will deform dramatically, which may cause a penetration failure of the hydrate-bearing slope. These findings are relevant to the long-term (millennial) safety of human beings and short-term (decadal) utilization of energy resources. |
IMIS is ontwikkeld en wordt gehost door het VLIZ.
