CO2 stability of Portland cement based well cementing systems for use on carbon capture & storage (CCS) wells

Rationalizing the impact of aging on fiber–matrix interface and stability of cement-based composites submitted to carbonation at early ages

“…According to Soroushian et al [13], CO 2 curing of cellulose fiber-cement has shown to enhance engineering properties, including dimensional stability of the final product. Furthermore, the consequences of carbonation are the stability of the mechanical behavior [13], densification of the cementitious matrix and reduction of its permeability (capillary) and porosity, which constitutes a positive process with respect to the pores sealing of the cementitious material [22]. In a previous study, Tonoli et al [23] showed the necessity to anticipate the fast carbonation for initial periods of cure, which would not allow time for the alkali to attack the cellulose fibers during the cement hydration.…”

Investigating temperature effect on degradation of well cement in HPHT carbonic acid environment

“…Previous similar studies (Stiles, 2006;Sauki and Irawan, 2010;Lesti et al, 2013) on compressive strength showed significant scattering in measurements. In order to minimize scattering and establish a reasonable trend, the values of compressive strength reported for each class of cement were averaged (three for unaged samples and six for aged samples).…”

“…Initially, diffusion and reaction controlled carbonation plays the dominant role in compressive strength development (Bruckdorfer, 1986;Krilov et al, 2000;Barlèt-Gouédard et al, 2006;Kutchko et al, 2007;Barlèt-Gouédard et al, 2009;Santra et al, 2009;Lesti et al, 2013;Mason et al, 2013).…”

“…In addition to the C-S-H polymorphs above, other structural forms, including an amorphous gel phase, might be produced at different temperatures and C/S ratios. Their structure, mineralogy and relative weights are characterized using techniques such as Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Neutron Magnetic Resonance (NMR) (Noik and Rivereau, 1999;Fabienne et al 2002;Le Saout et al, 2004, 2006a, 2006bNeuville et al, 2012;Lesti et al, 2013).…”

Modeling Pore Continuity and Durability of Cementitious Sealing Material

“…Besides, relevant issues that may contribute to the loss of integrity of the well, i.e., causing gas leakages in the existing cement slurry, are closely related to those actions that may introduce (micro-)cracks and affect the pore discontinuity causing alternative pathways for the C 02 to escape [11]. Interfaces between in-place cement slurry and rock formations, migration of the C 02-rich phase (aqueous, gas or liquid) through fractures or diffusion through the connected capillary pore space are considered to be most threatening mecha nisms that may harm the cement slurries sealing capacity of a well, causing loss of structural integrity [11][12][13][14][15], Carbonation degradation in cement-based materials is a coupled chemical equilibrium/diffusion phenomenon that may also include fracture mechanics [15]. Kinetics of transport-reaction processes are generally described by a simplified continuum (homogenized) model [16] where the actual evolution of the pore morphology are neglected.…”