Exploiting the temperature effects on low frequency electrical spectra of sandstone: A comparison of effective diffusion path lengths
Exploiting the temperature effects on low frequency electrical spectra of sandstone: A comparison of effective diffusion path lengths
复制标题
利用温度对砂岩低频电谱的影响：有效扩散路径长度的比较
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
N. Kettridge
中科院分区：
文献类型：
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作者：
A. Binley;S. Kruschwitz;D. Lesmes;N. Kettridge
最近的一些研究强调了利用电谱得出的弛豫时间来推断渗透性岩石的关键物理特性的潜在价值。迄今为止，大多数研究都假设晶粒尺寸或孔喉作为离子扩散过程长度尺度的度量，尽管这在最近的实验研究中受到了挑战。我们比较了三种砂岩的电谱，采用一种新方法，其中岩石样品的温度受到扰动，并测量弛豫时间作为温度的函数。我们的结果表明，对于此处测试的砂岩，有效扩散系数应被视为电曲折度的函数。这些发现可能有助于解释最近实验研究中在低渗透率岩石中观察到的明显的长弛豫时间。我们还强调在电谱的相关研究中需要考虑温度。
A number of recent investigations have highlighted the potential value of using relaxation times derived from electrical spectra to infer key physical properties of permeable rocks. To date, most studies have assumed a grain size or pore throat as a measure of the length scale of the ionic diffusive process, although this has been challenged in recent experimental investigations. We compare the electrical spectra of three sandstones, adopting a new approach in which the temperature of the rock samples is perturbed and the relaxation time measured as a function of temperature. Our results suggest that, for the sandstones tested here, the effective diffusion coefficient should be considered as a function of the electrical tortuosity. These findings may help explain the apparent long relaxation times observed in low-permeability rocks in recent experimental studies. We also highlight the need to account for temperature in related studies of electrical spectra.