The project is divided into 3 THEMES.
THEME 1: Novel tools to manufacture porous networks with integrated sensors. We developed a novel laser process that enables the rapid fabrication of porous media micromodels from low-cost borosilicate glass slides, with internal features ~30μm,
https://doi.org/10.3390/mi9080409(opens in new window) https://doi.org/10.1038/s41598-019-56711-5 &
https://doi.org/10.1016/j.jmatprotec.2020.116807(opens in new window)The fibre-optic sensor integration allowed to: (a) measure dynamic changes of pH & pressure at pore level; (b) measure absolute permeability within the micromodels; (c) investigate the effect of surface roughness on fluid flow; and (d) real-time observation of pH,
https://doi.org/10.3390/s21227493(opens in new window).
THEME 2: Dynamic studies of manufactured porous networks. The objective was to obtain a detailed understanding of pore-scale fluid displacement and reactive transport phenomena by jointly exploiting micromodels (THEME 1), flow and visualization facilities (THEME 2), and numerical modelling (from THEME 3). This will improve prediction of the numerical transport models at larger scales as well as improve understanding of subsurface transport phenomena.
We used hydrothermal batch vessels (Figure 3) to simulate deep saline aquifer conditions (250bar and 100°C) to understand how specific parameters can impact the rock-fluid geochemical interactions. Micro-CT imaging was used to determine changes in the structure of the rock samples (Figure 4).
Fluid displacement experiments were conducted in microfluidic devices (or micromodels) representative of natural reservoir rocks etched by laser onto glass substrates (Figure 5 a and b). A flow visualization experimental set-up to observe multiphase-flow phenomena was constructed (Figures 5 c and d) to perform flow experiments (100bars and 80°C) of CO2 and hydrogen (Figure 6).
The effects of several pore-scale properties were investigated conducting flow through experiments in micromodels using a unique micro-CT core flooding system (Figure 7 a and b) developed here. We also investigated the drying mechanisms and the extent of injectivity loss due to CO2 injection at the pore scale (
https://doi.org/10.3997/2214-4609.202113290(opens in new window)).
THEME 3: Novel integrated in-silico models of reactive transport. The objective was to develop transport models that address the extremely complex interplay of flow, transport and reactions occurring at from pore to core. We used computational fluid dynamics (CFD) as a direct numerical simulation (DNS) method to model multiphase flow in a real pore structure. To deal with the reactive transport modelling we used PHREEQC geochemical modelling code.
We investigated various fluid flow phenomena occurring during CO2 storage, e.g. viscous fingering (Figure 8a), and disconnected flow and ganglion dynamics (Figure 8b). The effect of wettability distribution on flow was lightened up, but it did not vanish as structural heterogeneity increases. It was shown that non-uniform wettability distribution is as important as structural heterogeneity, and their combined effect has a significant impact on fluid flow. The DNS studies were compared with and validated and good agreement was achieved, showing that the direct numerical simulations are a useful and accurate tool for predicting flow in the subsurface.
