Reservoir Condition Pore Scale Imaging of the Capillary Trapping of CO2

Abstract

We use micro-CT scanning to image, at the pore-scale, CO2 and brine in the pore-space of a carbonate rock. This technique is used for the examination of capillary trapping and for contact angle measurement. In the capillary trapping study the larger residual ganglia obeyed a power law size distribution, with a power law exponent of 2.287 ± 0.009, whereas smaller ganglia were underrepresented. Measurement of contact angle revealed the system to be weakly water wet at reservoir conditions, with a contact angle of 45 ± 6o. This distribution of contact angles can be explained by surface roughness heterogeneity at a range of length scales.