Vysledky laboratornich experimentu simulujicich injektovani CO2 do miocennich piskovcu labskeho horizontu ve videnske panvi (CR)

Geological storage of CO₂ is possible thanks to physicochemical processes, one of which is mineral trapping. Structural, stratigraphic or hydrodynamic mechanisms predominate at CO₂ injection whereas other processes evolve later on. The latter are governed primarily by flow of media in liquid and gaseous form driven by pressure and gravity or capillary forces, and heat transfer by convection and by diffusion. Transport of aqueous and gaseous species by advection and by molecular diffusion is considered.

After the CO₂ injection is complete, a number of capture mechanisms become significant. Part of CO₂ is captured by residual trapping as the carbonate solution moves away from the injection zone. At the same time, the gas is mixed with the formation water and dissolves in it (solubility trapping). The dissociation of CO₂ dissolved in reservoir waters enhances acidity of the environment that promotes interaction with the rock-forming minerals and rapid dissolution of carbonates (if present) in the acidified zone around the injection well. As a result, the content dissolved bicarbonates increases (ion capture) (Saeedi et al. 2011, Sayegh et al. 1990).

The ability of rock formations to absorb and permanently sequester CO₂ is a key technical and economic parameter evaluated within the frame of the CCS projects. The feasibility of CO₂ injection depends primarily on the porosity and permeability of reservoir rocks. Nevertheless, other aspects of CO₂ interaction with host rock, such as the dissolution and precipitation of minerals, also play a significant role (Benson – Cole 2002, Gaus 2010).

This work investigates geochemical reactions of sandstone reservoir rocks with CO₂-enriched solutions, focusing on the mineralogical transformations and their consequences for geological storage. Laboratory experiments were carried out using sandstone from the Dolní Bojanovice gas storage facility (Czech Republic) in contact with demineralized water. Dissolution of clay minerals and carbonates were identified as the main chemical reactions during the phase of CO₂ injection. These reactions resulted in an increased porosity of the rocks, which directly affects the capacity of the reservoir for the CO₂ storage.

References

Benson, S. B. – Cole, D. R. (2008): CO₂ sequestration in deep sedimentary formations. – Elements 4, 325–331.

Bujok, P. – Klempa, M. – Porzer, M. (2015): Výsledky nových petrofyzikálních měření – dílčí část. Příprava výzkumného pilotního projektu geologického ukládání CO₂ v České republice (REPP-CO₂) č. NF-CZ08-OV-1-006-2015, výstup V1.17. Ostrava. – MS VŠB-Technická univerzita. Ostrava.

Gaus, I. (2010): Role and impact of CO₂-rock interactions during CO₂ storage in sedimentary rocks. – Int. J. Greenh. Gas Control 4, 73–89.

Izeg, O. – Demiral, B. – Bertin, H. – Akin, S. (2008): CO₂ injection into saline carbonate aquifer formations I: Laboratory investigation. – Transp. Porous Media 72, 1–24.

Jiříček, R. (2002): Molasový vývoj alpsko-karpatské předhlubně a vídeňské pánve. – Explor. Geophys., Remote Sens. Environ. 9, 1–2, 1–179.

Krásný, J. – Císlerová, M. – Čurda, S. – Datel, J. – Dvořák, J. – Grmela, A. – Hrkal, Z. – Kříž, H. – Marszalek, H. – Šantrůček, J. – Šilar, J. (2012): Podzemní vody České republiky: regionální hydrogeologie prostých a minerálních vod. – Čes. geol. služba. Praha

Nehyba, S. (2015): Litofaciální analýza a sekvenční stratigrafie rezervoáru a jeho nadloží – zpráva a datový soubor uložený v geodatabázi, připravený k využití ve 3D modelu. Příprava výzkumného pilotního projektu geologického ukládání CO₂ v České republice (REPP-CO₂) č. NF-CZ08-OV-1-006-2015, výstup V1.9. – MS Masarykova univerzita. Brno.

Saeedi, A. – Rezaee, R. – Evans, B. – Clennell, B. (2011): Multiphase flow behaviour during CO₂ geo-sequestration: Emphasis on the effect of cyclic CO₂-brine flooding. – J. Pet. Sci. Eng. 79, 65–85.

Sayegh, S. G. – Krause, F. F. – Girard, M. (1990): Rock/fluid interactions of carbonated brines in a sandstone reservoir Pembina Cardium, Alberta, Canada. – SPE Form. Eval. 5, 399–405.