Borehole flowmeter and hydrogeophysics surveys: new possibilities for characterizing hydrogeological heterogeneities

Abstract

The research subject of this PhD thesis consists in the development and application of techniques for analyzing well‐log, well‐test, and tracer data to infer the distribution of hydrologic properties in heterogeneous geologic settings, including fractured rock and complex aquifer systems. This thesis is organized in an introductory section presenting the state of the art about heterogeneous geologic media characterization and a focus on flowmeter log analysis. The second chapter regards applications of an integrated surveying approach where an hydrogeophysical characterization was used for a complex aquifer in calcareous and gypsiferous formation. The most important topic is the joint use of the Electromagnetic Borehole Flowmeter (EBF) in single hole mode and the Ground Penetrating Radar in single and cross borehole configuration. The third chapter is a completion of the studies performed and described in chapter two, with an extensive study involving a conventional hydrogeological characterization (pumping test, core analysis) with flowmeter log in cross hole mode and its application to design and interpretation two tracer tests. The aim is to provide an approach to optimize a set of hydrogeological and geophysical survey techniques. In chapter four another application of the flowmeter log is presented. This application has been designed to monitor infiltration in the vadose zone of a sandy‐gravelly soil and use results as calibration data for the geophysical investigation (ERT and Georadar Borehole survey). This thesis involved coordination of laboratory and field work; collaboration with geophysicists, geochemists and geologists in interdisciplinary studies. Main applications of this work include advanced hydrogeological characterization, groundwater and vadose‐zone contaminant remediation as well as optimal utilization of water resources.