Comparative study of methods to estimate hydraulic parameters in the hydraulically undisturbed Opalinus Clay (Switzerland)
Comparative study of methods to estimate hydraulic parameters in the hydraulically undisturbed Opalinus Clay (Switzerland)
复制标题
水力未扰动 Opalinus 粘土水力参数估计方法的比较研究（瑞士）
DOI：
10.1007/s00015-016-0257-9
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发表时间：
2017
影响因子：
3.1
通讯作者：
Erik Sykes
中科院分区：
文献类型：
--
作者：
Catherine Yu;J. Matray;J. Gonçalves;D. Jaeggi;W. Gräsle;K. Wieczorek;T. Vogt;Erik Sykes
深孔(DB)实验提供了在瑞士Mont Terri岩石实验室的Opalinus Clay水力未扰动区获取水力参数的机会。通过248m深井BDB-1，采用三种方法估算Opalinus粘土地层及其边界地层的水力传导性和比容积值：应用泊松耶定律，包括岩石物理测量、压力时间序列频谱分析和现场水压试验。对于胶结系数在2到3之间的胶结系数，第一种方法给出的欧帕林斯粘土的渗透系数范围是2×10−14-6×10−13−和S−1。这些结果表明垂向变异性很小，而现场水力学试验表明S−1的值高达7×10−12 mm。岩心分析提供了均质基质水力性质的经济估计，但没有考虑更大尺度上的非均质性，如潜在的构造传导特征。通过光谱分析获得的特定储存值是一致的，在10−6m−1的数量级，而利用孔压信号之间的相移和增益的公式被发现不适合评估Opalinus Clay的水力传导性。得到的值在整体上与以前在岩石实验室获得的值吻合得很好。
The deep borehole (DB) experiment gave the opportunity to acquire hydraulic parameters in a hydraulically undisturbed zone of the Opalinus Clay at the Mont Terri rock laboratory (Switzerland). Three methods were used to estimate hydraulic conductivity and specific storage values of the Opalinus Clay formation and its bounding formations through the 248 m deep borehole BDB-1: application of a Poiseuille-type law involving petrophysical measurements, spectral analysis of pressure time series and in situ hydraulic tests. The hydraulic conductivity range in the Opalinus Clay given by the first method is 2 × 10−14–6 × 10−13 m s−1 for a cementation factor ranging between 2 and 3. These results show low vertical variability whereas in situ hydraulic tests suggest higher values up to 7 × 10−12 m s−1. Core analysis provides economical estimates of the homogeneous matrix hydraulic properties but do not account for heterogeneities at larger scale such as potential tectonic conductive features. Specific storage values obtained by spectral analysis are consistent and in the order of 10−6 m−1, while formulations using phase shift and gain between pore pressure signals were found to be inappropriate to evaluate hydraulic conductivity in the Opalinus Clay. The values obtained are globally in good agreement with the ones obtained previously at the rock laboratory.