Caprock Breach: A Potential Threat to Secure Geologic Sequestration of CO₂

Poromechanical behaviour of a surficial geological barrier during fluid injection into an underlying poroelastic storage formation

“…The stiffening action of the caprock diffuses the spatial distribution of heave. These effects have also been observed in the purely elastic modelling of caprock-storage horizon interaction [5][6][7]12], the surface heave becomes flattened and localized to the region of the injection region for the case when the caprock is not present [24]. It was also found that the ratio of the surface heave to the steady-state displacement was larger when a caprock was present.…”

“…hazardous waste [1][2][3]. Deep injection of fluidized forms of greenhouse gases into storage formations has been advocated as a means of mitigating the effects of climate change [4][5][6][7]. The process of injection into a porous storage formation pre-supposes that the fluid can be injected without detriment to the fabric of the porous medium and the geological setting can accommodate hydrodynamic trapping that is provided by a stable geological barrier (figure 1).…”

Isothermal Permeability of the Argillaceous Cobourg Limestone

“…Low permeability materials also feature prominently in concepts for very deep geologic disposal of hazardous wastes (Testa, 1994;Fuenkajorn and Daemen, 1996;Selvadurai, 2006). Similar sealing requirements are also necessary for re-habilitating abandoned wells that can be encountered in the geologic disposal of carbondioxide in fluidized forms (Pijaudier-Cabot and Pereira, 2013;Selvadurai, 2012Selvadurai, , 2013.…”

Thermo-poromechanics of a fluid-filled cavity in a fluid-saturated geomaterial

“…Alternatively, if the volumetric strain is positive (dilatation), then the yield stress will decrease, and the load path in the (P, q)-plane will intersect the yield surface when the effective pressureP is smaller than the radius of the yield surface. Hardening law (2.18) can be obtained as an approximation to the exponential hardening law 19) where e 0 = ϕ/(1 − ϕ) is the initial void ratio, λ and κ denote, respectively, the slope of the normal consolidation line and unload-reload compression lines in the isotropic compression test. Typical values of these parameters are λ = 0.2 and κ = 0.05.…”

“…The thermo-hydro-mechanical (THM) behaviour of geomaterials is important to many areas of environmental geomechanics, including deep geological disposal of heat-emitting radioactive wastes [1][2][3][4][5][6][7], frictional heating during earthquake slip [8][9][10], geothermal energy extraction [11,12], freezing action in soils [13][14][15][16] and geomechanics considerations related to geological sequestration of carbon dioxide [17][18][19]. In many instances, the scope of geoenvironmental engineering problems in these areas is such that recourse must be made to computational methods to solve any realistic environmental geomechanics problems.…”