Enhanced weathering of olivine in seawater: The efficiency as revealed by thermodynamic scenario analysis

Enhanced weathering of olivine has been suggested as a measure to lower the atmospheric CO2 level and it might also mitigate ocean acidification. This study aimed to characterise how olivine can weather in seawater, to elucidate the role of secondary precipitation and to ascertain the efficiency in terms of molar CO2 removal per mole of olivine...

Geochemical effects of SO2 during CO2 storage in deep saline reservoir sandstones of Permian age (Rotliegend) - A modelling approach

tGeochemical modeling was used to assess the impact of sulfur dioxide (SO2) in impure carbon dioxide(CO2) streams on fluid–rock interaction during storage in siliciclastic rocks of Permian age (Rotliegend).We focused on the impact of SO2on the porosity evolution, as well as on the trapping of CO2as solidmineral phase. Due to the lack of a...

Grain-rimming kaolinite in Permian Rotliegend reservoir rocks

Upper Rotliegend sediments of Permian age from the northeast Netherlands show moderate to good reservoir

Sensitivity of chemical cement alteration: modeling the effect of parameter uncertainty and varying subsurface conditions

To ensure the safety of a CO 2 storage site and containment of CO 2 in the subsurface, the integrity of wellbore materials must be maintained. Field and laboratory studies have shown CO 2 -induced reactivity of wellbore cement, but these results have to be extrapolated to the extended time span of CO 2 storage. Geochemical modeling provides a...

Geochemical evaluation of CO2 injection and containment in a depleted gas field

The short- and long-term geochemical impact of CO2 injection into a depleted gas reservoir (DGR) is investigated using reservoir/geochemical modeling with TOUGH2/TOUGHREACT and 1D kinetic diffusion modeling with PHREEQC (caprock/well-cement). Simulations of CO2 injection into the reservoir predict displacement and buoyancy of post-production CH4...

Effect of reactive surface area of minerals on mineralization and carbon dioxide trapping in a depleted gas reservoir

In this study, a long-term (up to 1000 years) geochemical modelling of subsurface CO2 storage was carried out on sandstone reservoirs of depleted gas fields in northeast Netherlands. It was found that mineral dissolution/precipitation has only a minor effect on reservoir porosity. In order to validate this, we focused specifically on the...

Reactive surface area in geochemical models - Lessons learned from a natural analogue

Many uncertainties exist in geochemical modeling. Mineral reactive surface area is one of the uncertain parameters. QEMSCAN analyses are performed on sandstone samples from a Dutch CO2 natural analogue to determine reactive surface areas. Geochemical modeling is performed using QEMSCAN surface areas and surface areas which are conventionally...

Model calibration on cement experiments at realistic CO2 storage conditions

Large scale implementation of CO2 storage can significantly reduce emission of greenhouse gasses into the atmosphere. However, safe and long-term containment of CO2 in storage reservoirs must be ensured. Wellbores in the subsurface present possible leakage pathways for CO2 to the surface and hence wellbore cement reactivity is of major concern....

Geochemical effects of impurities in CO2 on a sandstone reservoir

In most cases, CO2 captured from power plants or large industrial sources contains impurities. As purification of the stream is energy and cost intensive it is necessary to allow a certain level of impurities. The effects of impurities on (short- and long-term) geological storage are, however, uncertain. In this work, geochemical modelling with...

Geochemical evaluation of CO2 injection into storage reservoirs based on case-studies in The Netherlands

Over the past few years several geochemical evaluations of CO2 storage in Dutch potential reservoirs are carried out, including predictions of the short- and long-term impact of CO2 on the reservoir using geochemical modelling. The initial mineralogy of the reservoir is frequently obtained from core analysis and is then used to compute the...

Extent of immobilisation of phosphate during aeration of nutrient-rich, anoxic groundwater

Nutrient-rich exfiltrating groundwater may impose a heavy phosphate load on surface water systems. However, iron oxides that bind PO4 precipitate fast upon oxygenation at neutral pH and PO4 may also become bound in Ca precipitates following upon pH increase, so load estimates based on conservative behaviour during exfiltration will be...