Geophysical well logging has been applied for fracture characterization in crystalline terrains by physical properties measurements and borehole wall imaging. Some of these methods can be applied to monitor pumping tests to identify fractures contributing to groundwater flow and, with this, determine hydraulic conductivity and transmissivity along the well. We present a procedure to identify fractures contributing to groundwater flow using spontaneous potential measurements generated by electrokinetic processes when the borehole water head is lowered and then monitored while recovering. The electrokinetic model for flow through a tabular gap is used to interpret the measured data and determine the water head difference that drives the flow through the fracture. We present preliminary results at a test site in crystalline rocks on the campus of the University of São Paulo.

中文翻译：

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低噪声自发电位测井的裂缝流表征。

通过物理性质测量和井壁成像，地球物理测井技术已被用于结晶地形的裂缝表征。这些方法中的一些可用于监视泵送测试，以识别有助于地下水流动的裂缝，并由此确定沿井的水力传导率和渗透率。我们提出了一种程序，该程序使用降低井眼水位然后在恢复过程中进行监测的电动过程产生的自发电位测量来识别有助于地下水流动的裂缝。通过板状间隙流动的电动模型用于解释测得的数据并确定驱使水流过裂缝的水头差。