| Title | Investigation Of Fine Particles Mobilization During Geothermal Production from the Anglo-Paris Basin Albian Aquifer Using Coreflooding Experiments |
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| Authors | E. Rao D. Rousseau, R. Deschamps F. Seguin, J. Poulizac |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | This study investigated the mobilization of fine particles during geothermal production from the Anglo-Paris Basin Albian aquifer, that is suspected to entail injectivity decline at the reinjection side. It involved coreflooding experiments performed with clayey sand samples from Albian-aged "Greensand" formation. Sandpacks were prepared in a core holder equipped with a downstream filter and exposed to flow velocities varying from 0.3 m/day (in-depth aquifer flow) to about 200 m/day (near wellbore flow). The injection tests were performed primarily with a low salinity synthetic water representative of the aquifer (TDS = 0.17 g/L) and also with a high salinity water, to mimic the exposure of the near wellbore sediments to drilling fluids. The pressure drops across the porous medium and the downstream filter were recorded during injection. The filters were collected after each velocity or salinity step and analysed by SEM (images, chemical analysis) and XRD. At low and intermediate velocities, moderated particle production was observed. After a threshold velocity, massive particle production occurred and was associated to changes of the composition balance between clays and silica. Moreover, even for sandpacks primarily exposed to Albian water injection at low to high velocity, a salinity chock towards the high salinity water led, surprisingly, to additional and very significant particle production. These results show that both hydrodynamic and complex physicochemical interactions play a role in controlling particle release. They could help setting up new specifications for the production rates and well diameters as well as for the composition of the drilling fluids. |