Publication Name: Eastern Australian Basins Symposium III (EABS 2008)
Authors: R.F. Daniel and J.G. Kaldi
Date Published: September 2008
Number of Pages: 10
Abstract:
The petrophysical properties of cap rocks and intraformational barriers can constrain the carbon dioxide (CO2) containment volumes of potential geosequestration sites. Characterisation of regional seals and intraformational barriers requires an understanding of the seal capacity of the cap rock or barrier. Seal capacity is the capillary pressure (or column height) at which a trapped fluid commences to leak through a seal rock. Seal rocks are effective due to very fine pore and pore-throat sizes that result in low porosities and permeabilities. These in turn generate high capillary threshold pressures. High threshold pressures, together with wettability and interfacial tension (IFT) properties determine the final column height that a seal can hold. Wettability and IFT play an important role in the geological storage of CO2 through their effect on seal capacity (CO2 column height) with respect to capillary pressure, thereby controlling the potential for the movement of CO2 through the seal and affecting ultimate reservoir storage volumes.