CO2 sequestration in basalt: Carbonate mineralization and fluid substitution

Abstract

Geological sequestration of carbon dioxide in deep reservoirs may provide a large-scale option for reducing the emissions of this gas into the atmosphere. The effectiveness of sequestration depends on the storage capacity and stability of the reservoir and risk of leakage into the overburden. Reservoir rocks can react with a [Formula: see text]-water mixture, potentially resulting in the precipitation of minerals in the available matrix pore space and within pre-existing fractures. This induced mineralization may form internal seals that could help mitigate the leakage of [Formula: see text] into the overburden. For basaltic host rocks, carbonic acid partially dissolves minerals in the host rock, such as the calcium plagioclase mineral, freeing various cations (e.g., [Formula: see text] and [Formula: see text]) for later precipitation as carbonate cements (Gislason et al., 2010).