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

Klimaendringer er et presserende problem, og det er avgjørende å redusere CO2-utslipp. En lovende løsning er å lagre CO2 i geologiske reservoarer, som de salte akviferene i Nordsjøen, som kan holde store mengder CO2 og bidra til å dempe klimaendringene. En viktig fysisk prosess ved geologisk CO2-lagring kalles oppløsningsfanging, der CO2 løses opp i vann og synker når det blir tyngre, en prosess som forsterkes av konvektiv blanding. Dette er viktig fordi det akselererer CO2-lagring og forhindrer lekkasje. Å forstå denne prosessen gjør det mulig å planlegge lagringsoperasjoner bedre. Imidlertid er det utfordrende å modellere denne prosessen nøyaktig på grunn av de komplekse geologiske formasjonene. TIME4CO2-prosjektet kombinerer avanserte laboratorieeksperimenter, høyoppløselig dataanalyse og innovativ matematisk modellering. Gjennom tett integrasjon av disse er målet å forbedre simuleringsteknologi for CO2-lagring, og sikre nøyaktige forutsigelser av hvordan CO2 oppfører seg i undergrunnen under realistiske forhold. Dette vil bidra til å maksimere CO2-lagring og sikre langsiktig stabilitet.

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.