Chemo‐thermo‐mechanically coupled seismic analysis of methane hydrate‐bearing sediments during a predicted Nankai Trough Earthquake
Chemo‐thermo‐mechanically coupled seismic analysis of methane hydrate‐bearing sediments during a predicted Nankai Trough Earthquake
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DOI：
10.1002/nag.2527
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发表时间：
2016-11
影响因子：
4
通讯作者：
T. Akaki;S. Kimoto;F. Oka
中科院分区：
文献类型：
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作者：
T. Akaki;S. Kimoto;F. Oka
在本研究中，我们开发了一种数值方法，可以模拟含甲烷水合物沉积物产气过程中海床地面的动态行为。该方法可以描述地震过程中与孔隙流体流动有关的化学-热-力学-地震耦合行为，如从水合物到水和气体的相变、温度变化和地面变形。在本研究的第一部分，给出了所提出的方法的控制方程及其离散化。然后，对含水合物的沉积物进行了数值分析，以研究天然气生产过程中的动态行为。利用日本南海东部海槽第一次海上甲烷水合物开采试验的海床地面资料，确定了该海床的地质条件和材料参数。分析中使用了现场预测的地震。
In the present study, we have developed a numerical method which can simulate the dynamic behaviour of a seabed ground during gas production from methane hydrate‐bearing sediments. The proposed method can describe the chemo‐thermo‐mechanical‐seismic coupled behaviours, such as phase changes from hydrates to water and gas, temperature changes and ground deformation related to the flow of pore fluids during earthquakes. In the first part of the present study, the governing equations for the proposed method and its discretization are presented. Then, numerical analyses are performed for hydrate‐bearing sediments in order to investigate the dynamic behaviour during gas production. The geological conditions and the material parameters are determined using the data of the seabed ground at Daini‐Atsumi knoll, Eastern Nankai Trough, Japan, where the first offshore production test of methane hydrates was conducted. A predicted earthquake at the site is used in the analyses.