Figure 2: Mineral profiles across Caprock.
From: Observational evidence confirms modelling of the long-term integrity of CO2-reservoir caprocks
(a) Haematite (vol-%) profiles across the basal Carmel claystone. Solid curve is least-squares best fit to haematite vol-% profile to equation (6) adjusting ϕs, q and l (best fit values and 1σ uncertainties given on figure) with 1σ uncertainty on haematite of 7% relative, but a minimum uncertainty of 0.1 volume %. Dashed line shows profile for q=37 m−1 taken as lower limit as discussed in text. It is noteworthy that the upper 1 cm of the claystone is bleached adjacent to a CO2-bearing sandstone within the Carmel Formation. (b) Porosity calculated from SANS/VSANS measurements across caprock. (c) Tortuosity, τ2, (left-hand axis) and diffusivity De, (right-hand axis) calculated from SANS/VSANS measurements across caprock (see Methods).
