The relevance of dawsonite precipitation in CO ₂ sequestration in the Mihályi-Répcelak area, NW Hungary

Abstract

A natural CO2 reservoir system with a sandstone lithology in NW Hungary has been studied due to its similarities to a large saline reservoir formation that is widespread in the the Pannonian Basin (Central Europe) and is suggested to be one of the best candidates for industrial CO2 storage. A range of analytical techniques has been used on core samples from CO2-containing sandstone layers that represent a wide range of pressures (90–155 bar), temperatures (79–95°C) and pore fluid compositions (total dissolved solids between 18 000 and 50 700 mg l−1) to identify the mineralogy and textural characteristics of the natural reservoir.The only clear CO2-related feature in the studied lithology was the occurrence of dawsonite (NaAlCO3(OH)2) in a close textural relationship with albite. This is in clear agreement with our geochemical modelling results, which also underline the presence of albite as a precondition for the crystallization of dawsonite at the given P–T–X conditions. Our results suggest that, at least in the Pannonian Basin, dawsonite may be an important mineral for the safe sequestration of industrial CO2 in the subsurface.

Petroleum reservoir quality prediction: overview and contrasting approaches from sandstone and carbonate communities

“…Alternative models have recognized the limited complexing ability of organic acids and their scarcity in formation waters and now tend to assume a relatively closed system for sandstone diagenesis (Lander & Walderhaug 1999). In fact the degree of 'openness' is likely to be partly a function of the aqueous solubility of a given species in a sandstone with alumina, silica and TiO 2 being effectively immobile (and thus part of a closed system) while CO 2 is demonstrably part of an open diagenetic system in sandstones (Király et al 2016).…”

Granulometric properties of particles in Upper Miocene sandstones from thin sections, Szolnok Formation, Hungary

“…Storage of CO 2 in geological formations is a possible method to reduce the atmospheric content of this greenhouse gas, and beside tillage management and appropriate usage of soils (Bilandžija, D. et al 2017;Zacháry, D. et al 2018;Zacháry, D. 2019), geological sequestration provides a unique possibility to mitigate the carbon emission. Effects of CO 2 on the reservoir pore water-rock system must be well understood before industrial storage projects (Bachu, S. et al 2007;Arts, R. et al 2008;Király, Cs. et al 2016) are initiated.…”