InterPore2026

Pore-scale insights into dynamics of brine drying and salt precipitation induced by CO2 injection in porous media

20 May 2026, 14:20

15m

Oral Presentation (MS05) Physics of multiphase flow in diverse porous media MS05

Speaker

Tongke Zhou (Department of chemical engineering, University of Manchester)

Description

Deep saline aquifers are widely regarded as promising candidates for long-term CO2 sequestration, owing to their large storage capacity, favourable sealing conditions, and broad global distribution. Continuous CO2 injection is a prerequisite for the effective operation of carbon capture and storage (CCS) projects. However, the injection of dry CO2 can trigger evaporation of residual brine within the pore space, leading to salt precipitation in regions close to the injection well. The accumulation of salt crystals may partially or completely obstruct pore throats, causing permeability reduction, injectivity decline, and potential loss of storage efficiency. Consequently, a profound understanding of brine displacement, evaporation processes, and salt precipitation kinetics is essential for mitigating salt-induced formation damage and ensuring sustained CO2 injection.

In this work, a microfluidic study was performed to investigate the influence of the temperature and CO2 injection rate on the kinetics of brine evaporation and salt precipitation during CO2 injection into porous media. An in-house image processing framework was developed to quantitatively segment different phases within porous media, enabling characterisation of the temporal evolution and spatial distribution of both brine and precipitated salts, and thereby providing insight into the mechanisms governing brine drying and salt precipitation. Particular attention was given to the spatial distribution of salt crystals under different temperatures and gas flow rates. The results indicate that the distribution and connectivity of water clusters formed during the two-phase displacement stage are influenced by temperature and flow rate, and these features play a critical role in governing the subsequent salt precipitation kinetics. Elevated temperature and flow rate accelerate the drying process by enhancing evaporation and mass transfer, leading to an earlier onset of salt precipitation and increased precipitation kinetics. The results provide insights relevant to the optimisation of CO₂ injection strategies and to broader environmental implications.