Effects of solution supersaturation on barite precipitation in porous media and consequences on permeability: Experiments and modelling. (1st February 2020)

• Record Type: Journal Article
• Authors: Poonoosamy, Jenna; Klinkenberg, Martina; Deissmann, Guido; Brandt, Felix; Bosbach, Dirk; Mäder, Urs; Kosakowski, Georg
• Is Part Of: Geochimica et cosmochimica acta. Volume 270(2020)
• Page Start: 43
• Page End: 60
• Publication Date: 2020-02-01
• Subjects: Porosity clogging -- Celestine -- Solid solutions -- Reactive transport -- Nucleation; Geochemistry -- Periodicals; Meteorites -- Periodicals; Géochimie -- Périodiques; Météorites -- Périodiques; Geochemie; Astrochemie; Electronic journals; 551.905
• DOI: 10.1016/j.gca.2019.11.018
• Languages: English
• ISSNs: 0016-7037

Abstract

Highlights: SrSO4 replacement by BaSO4 in porous media and impact on permeability was studied. Supersaturation affect mineral growth mechanisms and subsequently permeability. The Kozeny-Carman equation as used in models underestimates permeability changes. Porosity-permeability equation involving a critical porosity could be a better alternative. Abstract: The understanding of porosity evolution in porous media due to mineral reactions and its impact on the transport of fluids and solutes is important, as this is a key factor in the long-term behaviour of underground engineered systems. The implementation of such coupled processes into numerical codes requires a mechanistic understanding of the relevant precipitation/dissolution processes in porous media and model validation with quantitative experiments. In this context, we conducted a series of flow-through column experiments to investigate the effect of supersaturation on barite precipitation mechanisms (e.g. nucleation) and consequential permeability changes. These experiments were modelled using the reactive transport code OpenGeoSys-GEM. Although the Kozeny-Carman equation is widely applied in numerical models describing porosity and permeability changes due to mineral dissolution and precipitation, it distinctively underestimated the permeability changes observed in the experiments. Instead, a porosity-permeability relationship involving a critical porosity at which the permeability decreases significantly had to be considered in the model. Post-mortem characterization (Scanning Electron Microscopy) highlighted the importance of including pore-scale information on passivation processes in order to get a better match between experimental and simulated results.