Granular experiments of thrust wedges: Insights relevant to methane hydrate exploration at the Nankai accretionary prism
Granular experiments of thrust wedges: Insights relevant to methane hydrate exploration at the Nankai accretionary prism
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推力楔的颗粒实验：与南开增生棱柱甲烷水合物勘探相关的见解
DOI：
10.1016/j.marpetgeo.2013.11.008
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发表时间：
2014
影响因子：
4.2
通讯作者：
T. Matsuoka
中科院分区：
文献类型：
--
作者：
Yasuhiro Yamada;K. Baba;A. Miyakawa;T. Matsuoka
甲烷水合物的成藏机制一直是日本南海增生棱柱体水合物研究的核心问题。在棱柱体增生过程中，地层流体的排出是重要的，这些含甲烷流体的运移对水合物的聚集具有很强的控制作用。两种类型的流体通道，粒间孔隙度和断层，需要进行评估，以了解水合物的积累。流体沿沿着断层的运移可以通过检查断层活动来部分模拟。我们的研究模拟的吸积过程中，使用两种颗粒的方法，近似的地质体作为一个集合的颗粒：（1）模拟实验，使用粒状材料，（2）基于离散元方法的数值模拟。模拟实验精确地再现了南海增生棱柱体地震剖面中观察到的棱柱体几何形状。数字图像相关分析表明，锋面逆冲总体上是活跃的，但老的构造也经常被重新激活。数值模拟产生的棱镜的几何形状类似的模拟实验。颗粒的速度分布显示出幕式断层和再活化的证据，但内部应力场表现出在变形过程中的棱柱体的更深的部分变化不大。模型显示的断层活动的频繁和实质性的变化表明，沿沿着断层表面的幕式流体流动。活跃的锋面逆冲表明，地层流体通常从棱柱体内部深处迁移到变形前缘，但也可能沿沿着重新活化的老断层移动。颗粒间渗透率也波动，因为它是由内部应力场的时间和空间变化控制的。然而，流体流动在棱柱的较深部分中可能相对稳定。
The accumulation mechanism of methane hydrates has been a central issue in previous hydrate research regarding the Nankai accretionary prism, southwest of Japan. Expulsion of formation fluids is significant during the prism accretion process, and the migration of these methane-bearing fluids exerts a strong control on the accumulation of hydrates. Two types of fluid pathways, inter-granular porosity and faults, need to be evaluated to understand hydrate accumulation. Fluid migration along faults can be partly modeled by examining faulting activity. Our study modeled the accretion process by using two granular methods that approximated the geologic body as an assemblage of particles: (1) analog experiments using granular materials, and (2) a numerical simulation based on the distinct element method. The analog experiments closely reproduced the prism geometry observed in seismic profiles across the Nankai accretionary prism. Digital image correlation analysis indicated that the frontal thrust is generally active but older structures are also frequently reactivated. The numerical simulations produced prism geometries similar to those of the analog experiments. The velocity distributions of the particles showed evidence of episodic faulting and reactivation, but the internal stress field exhibited little change in the deeper part of the prism during deformation. The frequent and substantial changes in fault activity displayed by the models indicate episodic fluid flow along fault surfaces. Active frontal thrusting suggests that formation fluids generally migrate from deep within the prism to the deformation front, but may move along reactivated older faults. Inter-granular permeability also fluctuates, as it is controlled by temporal and spatial variations in the internal stress field. However, fluid flow is likely to be relatively stable in the deeper segment of the prism.
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DOI：
--
发表时间：
2010
期刊：
Tectonophysics 484
影响因子：
--
作者：
Yamada;Y.;Yamashita;Y.;Yamamoto;Y.
通讯作者：
Y.
影响因子：
--
作者：
K. Ujiie;T. Hisamitsu;A. Taira
通讯作者：
K. Ujiie;T. Hisamitsu;A. Taira
影响因子：
3.7
作者：
G. Moore;A. Taira;A. Klaus;L. Becker;B. Boeckel;B. Cragg;A. Dean;C. Fergusson;P. Henry;S. Hirano;T. Hisamitsu;S. Hunze;M. Kastner;A. Maltman;J. Morgan;Y. Murakami;D. Saffer;M. Sánchez-Gómez;E. Screaton;David C. Smith;A. Spivack;J. Steurer;H. Tobin;K. Ujiie;M. Underwood;M. Wilson
通讯作者：
G. Moore;A. Taira;A. Klaus;L. Becker;B. Boeckel;B. Cragg;A. Dean;C. Fergusson;P. Henry;S. Hirano;T. Hisamitsu;S. Hunze;M. Kastner;A. Maltman;J. Morgan;Y. Murakami;D. Saffer;M. Sánchez-Gómez;E. Screaton;David C. Smith;A. Spivack;J. Steurer;H. Tobin;K. Ujiie;M. Underwood;M. Wilson
影响因子：
2.9
作者：
A. Miyakawa;Yasuhiro Yamada;T. Matsuoka
通讯作者：
A. Miyakawa;Yasuhiro Yamada;T. Matsuoka
影响因子：
5.8
作者：
N. Bangs;T. Shipley;S. Gulick;G. Moore;Shinichi Kuromoto;Y. Nakamura
通讯作者：
N. Bangs;T. Shipley;S. Gulick;G. Moore;Shinichi Kuromoto;Y. Nakamura