Anja Sundal

On Layer Specific CO2 Plume Distributions and Variability in Mineralization Potential

Candidate sandstone reservoirs for CO2 storage in the North Sea typically display layered geometries and varying degree of geological heterogeneity. The spatial distribution of depositional environments and the diagenetic imprint controls the reservoir properties. From correlation of well data (geophysical logs and rock samples) property grids may be constructed. Deterministic scenario modeling, taking the geological interpretation of facies into account, shows layer specific estimated dissolved volumes and lateral reaches of the plume. In comparison, standard averaging techniques such as harmonic mean for estimating the vertical permeability will yield a smaller plume front area and a mean vertical distribution. Using Eclipse 300 to illustrate the effects of averaging and PHREEQ-C to model the geochemical system, we demonstrate the range of mineralization potentials within the Johansen Formation (Northern North Sea) according to observed variations in mineralogy.