SIMULATING HETEROGENEOUS PROPERTY DISTRIBUTIONS FOR CARBON DIOXIDE INJECTION MODELING IN FRACTURED BASALTS

Assessing the suitability of a fractured basalt aquifer for geologic carbon sequestration requires a model domain that accounts for fracture heterogeneity in the target formation. Here we present data collection and simulation for assembling two- and three-dimensional property sets based on the spatial characteristics of low-volume pahoehoe basalts typical of the East Snake River Plain aquifer in southeast Idaho. Two-point covariance statistics for fracture zones were elicited from field data collected on pahoehoe basalt exposures at the Box Canyon field site resulting in an anisotropic model of spatial correlation. The model variogram was then used for sequential indicator simulation to construct 100 equally probable property sets. These property sets were used to specify the model domain for supercritical carbon dioxide injection. Results indicate that the model domain based on two-point sequential indicator simulation provides a reasonable representation of fracture zone heterogeneity suitable for carbon injection modeling.