Influence of CO₂‐wettability on CO₂ migration and trapping capacity in deep saline aquifers

Abstract

Abstract CO 2 migration and trapping capacity in deep saline aquifers are highly influenced by various rock and fluid parameters. One of the key parameters, which has received little attention, is CO 2 ‐wettability. We thus simulated the behavior of a CO 2 plume in a deep saline aquifer as a function of rock wettability and predicted various associated CO 2 migration patterns and trapping capacities. We clearly show that CO 2 ‐wet reservoirs are most permeable for CO 2 ; CO 2 migrates furthest upwards and the plume has a candle‐like shape, while in a water‐wet reservoir the plume is more compact and rain‐drop shaped. Furthermore, higher residual trapping capacities are achieved in water‐wet rock, while solubility trapping is more efficient in CO 2 ‐wet rock. We thus conclude that rock wettability has a highly significant impact on both CO 2 migration and trapping capacities and that water‐wet reservoirs are preferable CO 2 sinks due to their higher storage capacities and higher containment security. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd.