MuSET: A multiparameter and high precision sensor for downhole spontaneous electrical potential measurements |
| |
| Authors: | Philippe A Pezard Stéphanie Gautier Tanguy Le Borgne Bruno Legros Jean-Luc Deltombe |
| |
| Institution: | 1. UMR 5243, CNRS, Géosciences Montpellier, université de Montpellier, place Eugène-Bataillon, cc049, 34095 Montpellier cedex 05, France;2. ALT, route de Niederpallen, 8506 Redange-sur-Attert, Grand-Duché du Luxembourg, Luxembourg;3. Géosciences Rennes, université Rennes, 1263, avenue du Général-Leclerc, 35042 Rennes cedex, France |
| |
| Abstract: | On the basis of an existing multiparameter borehole fluid sensor (p, T, Cw, pH, Eh), a new downhole tool designed for 200 bars and 75 °C was developed to measure the spontaneous electrical potential in situ with great precision (better than a μV). To this end, the new sensor is based on the use of unpolarizable Pb/PbCl2 electrodes either at the surface or downhole. In situ testing has demonstrated a capacity to identify several subsurface sources of natural electrical potential such as diffusion ones (membrane potential in the presence of clays, Fickian processes due to pore fluid salinity gradients), or else the electrokinetic mechanisms with gradients in pore fluid pressure. As a consequence, Multi-Sensors Electrical Tool (MuSET) might be used as an “electrical flowmeter” sensitive to both horizontal and vertical fluid flow in a vertical borehole. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
