The elastic wave velocity response of methane gas hydrate formation in vertical gas migration systems
The elastic wave velocity response of methane gas hydrate formation in vertical gas migration systems
复制标题
垂直气体运移系统中甲烷水合物形成的弹性波速度响应
DOI：
10.1088/1742-2140/aa6493
复制
发表时间：
2017-03
影响因子：
1.4
通讯作者：
Wang J. S.
中科院分区：
文献类型：
--
作者：
Bu Q. T.;Hu G. W.;Ye Y. G.;Liu C. L.;Li C. F.;Best A. I.;Wang J. S.
水合物沉积物的弹性波速度对于地球物理勘探和资源评价具有重要意义。无论是在海底还是在陆地冻土区，甲烷气体运移过程在水合物地质成藏系统中起着重要作用，其对沉积物弹性波速度的影响有待进一步研究。因此，高压实验室装置的开发，以模拟天然甲烷气体通过沉积物的连续垂直迁移。分别用时域反射法（TDR）和超声波透射法同步测量了沉积物中天然气水合物形成过程中的含水饱和度（Sh）和超声波纵横波速度（Vp和Vs）。结果进行了比较，以前发表的实验室数据中获得的静态封闭系统。这表明在水合物形成过程中，天然气垂向运移体系中含水合物沉积物的速度略低于封闭体系中的速度。在封闭体系中，纵波速度随水合物饱和度的增加而增加，而在垂向运移体系中，纵波速度随水合物饱和度的增加呈现出快-慢-快的变化规律。有效介质速度模型很好地描述了观测到的速度，由此推断水合物形态的变化导致了天然气运移系统中快-慢-快的速度响应。水石膏首先在颗粒接触处形成水泥，然后在孔隙空间内生长（漂浮），最后再次生长到与孔壁接触。研究表明，水合物形态是影响天然气垂直运移系统中甲烷水合物形成的弹性波速度响应的关键因素。
Knowledge of the elastic wave velocities of hydrate-bearing sediments is important for geophysical exploration and resource evaluation. Methane gas migration processes play an important role in geological hydrate accumulation systems, whether on the seafloor or in terrestrial permafrost regions, and their impact on elastic wave velocities in sediments needs further study. Hence, a high-pressure laboratory apparatus was developed to simulate natural continuous vertical migration of methane gas through sediments. Hydrate saturation (S h) and ultrasonic P- and S-wave velocities (V p and V s) were measured synchronously by time domain reflectometry (TDR) and by ultrasonic transmission methods respectively during gas hydrate formation in sediments. The results were compared to previously published laboratory data obtained in a static closed system. This indicated that the velocities of hydrate-bearing sediments in vertical gas migration systems are slightly lower than those in closed systems during hydrate formation. While velocities increase at a constant rate with hydrate saturation in the closed system, P-wave velocities show a fast–slow–fast variation with increasing hydrate saturation in the vertical gas migration system. The observed velocities are well described by an effective-medium velocity model, from which changing hydrate morphology was inferred to cause the fast–slow–fast velocity response in the gas migration system. Hydrate forms firstly at the grain contacts as cement, then grows within the pore space (floating), then finally grows into contact with the pore walls again. We conclude that hydrate morphology is the key factor that influences the elastic wave velocity response of methane gas hydrate formation in vertical gas migration systems.
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影响因子：
3.5
作者：
B. Tucholke;G. Bryan;J. Ewing
通讯作者：
B. Tucholke;G. Bryan;J. Ewing
影响因子：
3.5
作者：
T. Shipley;M. H. Houston;R. Buffler;F. J. Shaub;K. Mcmillen;J. Ladd;J. L. Worzel
通讯作者：
T. Shipley;M. H. Houston;R. Buffler;F. J. Shaub;K. Mcmillen;J. Ladd;J. L. Worzel
影响因子：
5.2
作者：
J. Dvorkin;M. Prasad;A. Sakai;D. Lavoie
通讯作者：
J. Dvorkin;M. Prasad;A. Sakai;D. Lavoie
DOI：
--
发表时间：
2008
期刊：
--
影响因子：
--
作者：
Wang Jia-sheng
通讯作者：
Wang Jia-sheng
影响因子：
--
作者：
M. Eaton;D. Mahajan;R. Flood
通讯作者：
M. Eaton;D. Mahajan;R. Flood