Application of gravity currents to the migration of CO2 in heterogeneous saline formations

Gravity currents form when carbon dioxide is injected into a saline formation beneath a sealing caprock, since under most conditions the injected CO2 is significantly less dense than the formation water. The phenomena of gravity currents are examined for the simplest kind of heterogeneity, that of two horizontal layers of contrasting permeability. The results of numerical simulations of single phase flow are compared with both laboratory experiments and analytical predictions. The results on gravity currents are applied to the spreading of the gas phase CO2 and also to the slumping of the dissolved CO2. (C) 2009 Elsevier Ltd. All rights reserved.