THESIS OF Ariane Suzzoni*
The interaction between surfactants and clay minerals is a well-known source of problems in the field of enhanced oil recoverya since it can induce a modification in the injected formulations and a decrease in productivity due to pore plugging. This phenomenon also concerns the pollution remediation sector, in both land and water environments. The aim of the research conducted for this thesis was to gain a better understanding of the mechanisms at play.
Initially, the interaction mechanisms were studied via tests involving the aqueous phase adsorption of anionic surfactants on the surface of mineral clays (kaolinite and illite), which are simultaneously representative and very different from one anotherb (1). The influence of surfactant concentration on aqueous suspension stability was then studied via a combination of sedimentation monitoring over time, rheological measurements and small angle X-ray scattering (SAXS) experimentsc.
For kaolinite, these measurements revealed a dispersion of the particles in the presence of surfactants. Analysis of the microscopic structure of suspensions
using SAXS reveals a strong correlation between surfactant concentration and the orientation of individual particles within sediments (figure), with consequences for petrophysical and confinement properties.
Such behavior was not observed with illite suspensions, in which there was little particle orientation within sediments. Beyond the observations made, combining the data acquired relating to these colloidal dispersions made it possible, for the first time, to link their macroscopic behavior to adsorption, wettability and particle orientation properties.
This experimental work is therefore a first stage that has provided a raft of useful information for effluent treatment, separation by flotation and any other process involving flows in porous media.
a - Or EOR.
b - Particles of these clays differ in terms of their size, shape factors and the charges they carry.
c - Particularly at SOLEIL Synchrotron.
*Thesis entitled "Evolution of the structure of clay minerals during their interactions with anionic surfactants"
(1) A. Suzzoni, L. Barre, E. Kohler, P. Levitz, L. J. Michot, J. M’Hamdi, Colloids and Surfaces A: Physicochemical and Engineering Aspects, volume
556, Nov. 2018.
DOI : 10.1016/j.colsurfa.2018.07.049
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