PhD thesis in experimental geophysics H/F

As a national geological service, the BRGM is the benchmark public establishment in the applications of Earth sciences to manage the resources and risks of the soil and subsoil (www.brgm.fr ). Its action is oriented towards scientific research, support for public policies and international cooperation.

The BRGM has extensive expertise in the field of remediation of polluted soils, and in particular in the use of non-Newtonian fluids (e.g. surfactants, foams). Its work is supported in particular by various experimental setups, ranging from the laboratory to the pilot scale.

The UMR METIS laboratory is mainly interested in "continental surfaces", the circulation of water, elements and pollutants in environments, which can be strongly impacted by man, but which are also a sensitive and essential resource for the development of the society. Within the laboratory, the geophysics team is particularly active in methodological development (instrumentation, prospecting, modelling). Its skills cover the different methods of hydrogeophysics: electric, electromagnetic (low and high frequency), magnetic, seismic and thermal methods.

The UMR I2M laboratory brings together research teams in mechanics and materials from the Bordeaux center of “Arts et Métiers ParisTech”, Bordeaux University and ENSCBP. Its research work is mainly oriented around the following research themes: (1) composites, non-destructive testing, process engineering; (2) buildings, civil engineering and energy. Within the laboratory, the TREFLE department brings together most of the activity in the fields of fluid mechanics and transfers, and in particular reactive transfers within porous media.

BRGM, UMR I2M and UMR METIS are jointly looking for a PhD student to contribute to the broadband electrical characterization of foams used for the remediation of hydrocarbon-polluted aquifers.

As part of your PhD work, you will be mainly responsible for:

- Participating in the development of measurement cells over a wide frequency band (several different technologies);

- Carrying out laboratory experiments on foam formulations with and without porous media, with and without the presence of contaminants;

- Developing models linking the measured electrical properties to the hydrodynamic parameters characterizing the flow of foams in the porous medium;

- Communicating the results through participation in international conferences and writing of A-rank scientific publications.

Thesis subject : Broadband electrical characterization of foam used for remediation of hydrocarbon-polluted aquifers

This thesis is part of a project called BBFOAM, funded by the French National Agency. The main objective of the BBFOAM project is to establish the founding knowledge for electrical monitoring of foams in the subsurface. Due to their unique properties (density, viscosity, interfacial tension, capillarity), we intuit that foams will exhibit rich electrical responses over a wide frequency band. Their polarization signatures especially could be distinguished from the electrical signature of soil.

The project will fill the lack of data and understanding of the broadband electrical response of foams in porous media, from mHz to GHz. We propose to develop a new methodology to follow the injection of different types of foams in porous media by implementing a series of controlled experiments at the laboratory scale and by developing new elementary models explaining the measurements.

You will be in charge of developing experimental devices and performing measurements on: (1) foams alone, (2) foams in the presence of a porous medium; and (3) foams in a porous medium in the presence of a pollutant. You will also lead the interpretation of results and explore potential links between foam properties (with and without porous media) and geophysical results by testing and adapting various modeling approaches developed in the literature.