Unlocking maximal geological CO2 storage through experimentally validated mathematical modeling of dissolution and convective mixing

Climate change is a pressing issue, and reducing CO2 emissions is crucial. One promising solution is storing CO2 in geological reservoirs, such as the saline aquifers in the North Sea, which can hold vast amounts of CO2 and help mitigate climate change. A key physical process of geological CO2 storage is called dissolution trapping, where CO2 dissolves in water and sinks as it becomes heavier, a process amplified by convective mixing. This is important because it accelerates CO2 storage and prevents leakage. Understanding this process allows for better planning of storage operations. However, accurately modeling it is challenging due to the complex nature of geological formations. The TIME4CO2 project combines advanced laboratory experiments, high-resolution data analysis, and innovative mathematical modeling. Through tight integration of these, the goal is to improve simulation technology for CO2 storage, ensuring accurate predictions of how CO2 behaves in the subsurface under realistic conditions. This will help maximize CO2 storage and ensure long-term stability.

Geological CO2 storage is a key component of any climate change mitigation strategy for reducing CO2 emissions, highlighted in the latest IPCC report. Geological reservoirs, like saline aquifers in the North Sea, offer vast storage capacities. A central beneficial phenomenon in geological carbon storage and primary focus of the TIME4CO2 project is dissolution trapping enabled by buoyancy-driven convective mixing, both accelerating storage and preventing leakage. As identified in two recent benchmark initiatives, effective and efficient numerical modeling of dissolution taking into account anisotropic dispersion remains a key scientific challenge in computational reservoir modeling. Moreover, previous experimental studies of convective mixing in literature have focused on overly idealized conditions. There remains a lack of high-quality laboratory data of convective mixing in active and heterogeneous aquifers for quantitative model validation. Through an interdisciplinary approach, combining unprecedented laboratory experiments, high-resolution image-based data analysis, and innovative mathematical modeling, the TIME4CO2 project aims to "advance simulation technology for CO2 storage, capturing spatio-temporal evolution of dissolution processes and convective mixing, validated against high-resolution complex meter-scale laboratory experiments". TIME4CO2 will develop novel efficient numerical methods for multi-phase flow in porous media subject to anisotropic dispersion and convective mixing. The methodology will be validated against meter-scale laboratory CO2 storage experiments with emphasis on reservoir heterogeneity, dynamic injection, and background flow. Quantitative model validation will be performed using physics informed optimal transport metrics. This toolset will allow for probing for maximal CO2 storage and scrutinize timescales central for geological carbon storage from onset of dissolution to stable stratification after reinjection.