It is well understood that spatially correlated heterogeneities can affect large-scale CO2 migrations in geological sequestration.However, recent experimental observations from high resolution Computed Tomography (CT)imaging have shown heterogeneities at the millimeter scale in natural sandstone core samples. These heterogeneities have a high degree of randomness without distinct spatial patterns, and they appear relatively homogeneous at a larger scale. As a result, such heterogeneities tend to be ignored in core analysis and in flow simulations. In this study, we show that ignoring such small-scale heterogeneities can lead to significant overestimations of CO2 plume speed in modeling buoyancy-driven CO2 migrations. For the representative examples we study, the overestimation can be a factor of two or larger.
Li, B., & Benson, S. M. (2014). Small-scale heterogeneities and buoyancy-driven CO2 migration in geological storage. In Energy Procedia (Vol. 63, pp. 3608–3615). Elsevier Ltd. https://doi.org/10.1016/j.egypro.2014.11.391