Understanding the role of geochemical reactions in geological carbon sequestration (ECR Collaboration Fund)

Dr Senyou An (Research Associate at Imperial College London) received funding in the UKCCSRC Collaboration Fund Call 4 to collaborate with Porelab (NTNU+UiO).

First, I would like to express my great thanks to UKCCSRC for jointly supporting my one-month visit to PoreLab (NTNU+UiO). PoreLab is a multidisciplinary institution focusing on the porous media field with excellent researchers from different backgrounds. During my visit, the warm welcome and well-planned schedule made this ECR Collaboration fund more meaningful to me. I appreciated the fruitful discussion and collaboration.

Carbon neutrality is a long-term strategy to save Planet Earth from the imminent danger of catastrophic “global warming”, as highlighted in the Paris Agreement by involved governments. Carbon capture and storage (CCS) is an effective technique which lets us minimise the carbon footprint of using fossil fuels while reaching this long-term goal. Among available options for CCS, deep saline aquifers have the highest capacity. Rock-fluid interactions play an important role in the carbon fate in geological systems. The geochemical equilibrium of the aquifer is disturbed by injecting CO₂, which promotes rock-fluid interactions. These interactions can either improve the rate of carbon sequestration or result in the formation of damage and injectivity decrease in the aquifer, which is usually undermined. Also, one can provide a better estimation of the optimum rate of CO₂ injection as well as the capacity of the target aquifer for carbon sequestration by taking the rock-fluid interactions into account.

Microfluidic experimental setup at UiO

Upscaling geochemical reactions in complex CO₂-water-rock systems is still a challenging problem. Many questions such as determining effective rock reactive surface, upscaled reaction rate and permeability impairment/generation due to precipitation/dissolution and the effect of pore-scale heterogeneity on the process are still open to be addressed. To this end, pore-scale reactive flow and transport modelling play an important role in upscaling local reactions on the rock surface (pore-scale) to the continuum scale to be used in field-scale simulators for CCS. Integrating reactive pore-scale models with the continuum-scale flow provides a unique opportunity to delineate the impact of pore-scale physical and chemical processes on upscaled behaviour to improve the predictive capabilities of field-scale simulators for carbon storage.

During the visit, we carried out the experimental validations and analysis at the core scale in the laboratory (PoreLab). Using available numerical results of my research, we experimentally built pore-scale models to investigate the solute transport, non-Newtonian fluid flow, as well as heat transfer in the heterogenous porous material. Also, several potential projects related to pore-scale hydrodynamics considering geochemical reactions are in the pipeline to be carried out. The results of the validated pore-scale model can be used in different scenarios for upscaling reactive transport. Last but not least, I wish to thank all PoreLab members for their great support.

Trondheim tour with Dr Marcel Moura, Dr Hamidreza Erfani and Dr Omar Brizuela

*****************************

PoreLab websites: https://porelab.no/

Useful open codes (partially from PoreLab): https://github.com/OPM

My presentation abstract at PoreLab: https://porelab.no/2022/10/06/porelab-lecture-with-dr-dr-senyou-an-on-multi-scale-flow-and-transport-dynamics-in-porous-media/

Published paper: https://doi.org/10.1016/j.cej.2020.127235