张艳^1,2,3,,
符力耘⁴,
陈学忠⁵,
曹呈浩^1,2,3,
赵连锋^1,2,3,
马玉川⁶
1. 中国科学院地质与地球物理研究所, 中国科学院地球与行星物理院重点实验室, 北京 100029
2. 中国科学院大学, 北京 100049
3. 中国科学院地球科学研究院, 北京 100029
4. 中国石油大学(华东)地球科学与技术学院, 山东青岛 266580
5. 中国地震局地球物理研究所, 北京 100081
6. 中国地震台网中心, 北京 100045

基金项目: 中国自然科学基金（41874161，41604035）和中国科学院战略性先导科技专项（B类）（XDB10010401）联合资助


详细信息

作者简介: 张艳, 女, 1983年生, 副研究员, 主要从事岩石物理和地震地下流体研究.E-mail:evezhangyan@mail.iggcas.ac.cn

中图分类号: P641

收稿日期:2017-09-16
修回日期:2018-04-13
上线日期:2019-01-05

Study of different hydraulic response models to large earthquakes in two adjacent wells: the effect of shales

ZHANG Yan^1,2,3,,
FU LiYun⁴,
CHEN XueZhong⁵,
CAO ChengHao^1,2,3,
ZHAO LianFeng^1,2,3,
Ma YuChuan⁶
1. Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
3. Institutions of Earth Science, Chinese Academy of Sciences, Beijing 100029, China
4. China University of Petroleum(East China), School of Geosciences, Qingdao Shandong 266580, China
5. Institute of Geophysics, China Earthquake Administration, Beijing 100081, China
6. China Earthquake Networks Center, Beijing 100045, China


MSC: P641

--> Received Date: 16 September 2017
Revised Date: 13 April 2018
Available Online: 05 January 2019


摘要
摘要:大地震引起了左家庄和宝坻（相距~50 km）两井中截然不同的同震水位响应.我们用水位的气压和潮汐响应来分析解释此现象.结果表明，宝坻井的观测含水层中存在页岩，且此井受裂隙影响很大，储水效应较差.页岩的复杂裂隙或者各向异性可能会导致此井观测含水层处于半封闭状态，从而导致垂直向排水的发生.通过多方计算分析后，我们将这两口井划分为两种模型-1.水平流动模型；2.水平流动+垂直流动的混合流动模型.由于裂隙影响，宝坻井的观测含水层介质与外界的水力沟通性在震前就较强（震前渗透率就比较大），所以宝坻井观测含水层与外界的孔隙压差异较小，导致同震渗透率上升较小甚至没有变化，这些因素是导致该井同震水位变化幅度总是非常微小的原因.
关键词: 潮汐/气压响应/
水平流/垂直流模型/
水位/
页岩/
大地震

Abstract:Large earthquakes induced different co-seismic water-level responses in Zuojiazhuang and Baodi wells (~50 km apart). Barometric responses and tidal responses are used to explain this anomaly in this study. After analysis, shale was found in the aquifer lithology of well Baodi. The well is found to be significantly influenced by fractures, and has a poor water confining ability. It is likely that the complex fractures or anisotropy of shale lead to a semi-confined aquifer, and as calculated, vertical drainage occurred in the aquifer stratum. Therefore, we separate the 2 wells into 2 models-the horizontal flow model, and the (pure) horizontal flow + (pure) vertical flow model. Because of the influence of fractures, the aquifer medium of well Baodi has a good hydraulic connection with the outside field even before the occurrence of earthquakes, thus, the difference in pore pressure between the well aquifer and the outside field is small, leading to a tiny (or even none) co-seismic permeability increase, and those might be the reasons why the co-seismic water-level changes in Baodi well are always small and unclear.
Key words:Tidal/barometric responses/
Horizontal/vertical flow model/
Water level/
Shale/
Large earthquakes



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