Geochemical modeling of carbonation of hydrated oil well cement exposed to CO 2 -saturated brine solution

Wellbore integrity in a saline aquifer: Experimental steel-cement interface degradation under supercritical CO2 conditions representative of Brazil’s Parana basin

“…5A and B). As CO 2 -rich brine percolates through the porous cement structure, CaCO 3 formation from the consumption of portlandite and C-S-H is observed (Duguid et al, 2011;Koukouzas et al, 2017). These reactions (Eqs.…”

“…2.4.1. Cement paste carbonation Cement paste carbonation processes are widely known and the main reactions lead to the degradation of the Ca(OH) 2 or portlandite (CH) and calcium silicate hydrate (C-S-H) phases, to produce different calcium carbonate (CaCO 3 ) polymorphs such as calcite, aragonite and vaterite (Duguid et al, 2011;Koukouzas et al, 2017). These reactions are represented by Eqs.…”

“…Morphology and porosity in wellbore materials play key roles in cement and steel bonding (Silva and Milestone, 2018b). Both properties can be altered as the degradation in CO 2 -rich brine progresses, definitely compromising the cement-casing cohesion and wellbore integrity (Bagheri et al, 2018;Koukouzas et al, 2017). Fig.…”

“…In order to ensure the effectiveness of the carbon storage process for hundreds to thousands of years, it is necessary to properly choose the host geological formation (Barlet-Gouédard et al, 2009;Carey et al, 2010). In this context, the Intergovernmental Panel on Climate Change (IPCC) points out that coal seams, depleted oil and gas fields, and deep saline aquifers should be adequate subsurface reservoirs for CCS operations (Koukouzas et al, 2017;Metz et al, 2005). Among them, saline aquifers show the highest storage capacity while at the same time, they are widespread over the world (Laumb et al, 2016;Metz et al, 2005).…”

“…Currently, most studies only focus on one of the wellbore system materials (formation-cement-casing) and, although significant work has been done to assess the integrity of the formation-cement interface Milestone, 2018a, 2018b), there is a lack of information about the integrity of the cement-casing interface and how the materials interact during the CO 2 degradation process (Jobard et al, 2018;Tremosa et al, 2017). Studies of cement carbonation (Bihua et al, 2018;Koukouzas et al, 2017) and steel casing corrosion (Nešić, 2007) are numerous. However, the evaluation of the cement-casing interface integrity is significantly limited (Asahara et al, 2013;Carey et al, 2010Carey et al, , 2009Mito et al, 2015;Nakano et al, 2016Nakano et al, , 2014Ren et al, 2016;Wolterbeek et al, 2016Wolterbeek et al, , 2013Wolterbeek and Raoof, 2018).…”