Periodic Reporting for period 1 - COCONUT (Colloidal control of multi-phase flow in geological porous media)
Berichtszeitraum: 2022-10-01 bis 2025-03-31
Small-scale solid particles (nanometals, fine particles, bacteria, viruses, asphaltenes..) also referred to as colloids are ubiquitous in geological porous media. The nature of the particles can vary significant and their presence in the soils and subsurface may be desired or on the contrary, avoided. They can be manufactured for engineering purposes or generated in situ. Such particles have an incredible potential to remobilize non-aqueous phase trapped by capillary forces in soils and the subsurface, and then to remediate contaminated groundwater or to enhance oil recovery. Their use in daily engineering, however, is still underexploited because the lack of knowledge regarding their transport mechanisms is an obstacle to precise control of two-phase flow. Importantly, the presence of colloidal particles flowing in the subsurface challenges the standard models of flow and transport in porous media. The objective of COCONUT is to decipher the mechanisms leading to the displacement of fluids trapped in an unsaturated porous media in the presence of colloids using pore-scale modelling and microfluidic experiments, and eventually proposes advanced remediation techniques.
The COCONUT project uses a combined modelling-experimental strategy focusing on the pore-scale mechanisms and on the upscaling to the continuum-scale. The project is multi-disciplinary and uses computational and experimental sciences, fluid dynamics, electrochemistry, and mathematics.
* We developed microfluidic experiments to investigate two-phase flow as well as particulate transport and retention in porous media. The experimental setup allowed to investigate pore-clogging mechanisms due to the injection of sub-micron size particles as a function of flow rate and fluid salinity.
* We developed a novel kind of simulator to simulate particulate transport in porous media at the pore-scale. The model relies on a resolved-unresolved CFD-DEM approach and includes colloidal forces.
* We are developing column scale experiment to investigate two-phase flow and the retention of particle in 4D using synchrotron radiation facilities.
* We developed microfluidic experiments to investigate two-phase flow as well as particulate transport and retention in porous media. The experimental setup allowed to investigate pore-clogging mechanisms due to the injection of sub-micron size particles as a function of flow rate and fluid salinity.
* We developed a novel kind of simulator to simulate particulate transport in porous media at the pore-scale. The model relies on a resolved-unresolved CFD-DEM approach and includes colloidal forces.
* We are developing column scale experiment to investigate two-phase flow and the retention of particle in 4D using synchrotron radiation facilities.
The project will reveal the transport mechanisms leading to the remobilization of contaminants trapped by capillary forces using unprecedented high-resolution imaging and modeling techniques. The multi-scale multi-physics modelling tools developed during the project are released in open-source with the objective to gather a community of users.
Thanks to our microfluidic experiments, we have observed a new kind of pore-clogging mechanisms. Under certain conditions that we have determined, particle deposit on the porous matrix forming a dendrite that growths up to pore-clogging. This mechanism was suspected but it has never been observed before.
The CFD-DEM simulator that we developed is able to capture the three main pore-clogging mechanisms (i.e. sieving, bridging, aggregation). Applications go above the subsurface porous media. The code is generic and can be applied to other fields including batteries, particulate filters, biological media...
Thanks to our microfluidic experiments, we have observed a new kind of pore-clogging mechanisms. Under certain conditions that we have determined, particle deposit on the porous matrix forming a dendrite that growths up to pore-clogging. This mechanism was suspected but it has never been observed before.
The CFD-DEM simulator that we developed is able to capture the three main pore-clogging mechanisms (i.e. sieving, bridging, aggregation). Applications go above the subsurface porous media. The code is generic and can be applied to other fields including batteries, particulate filters, biological media...