Investigation of Permeability Change Due to Salt Precipitation during CO2 Sequestration

Carbone capture and sequestration (CCS) is one of the most effective methods for reducing CO2 emissions into the atmosphere. Saline aquifer offers the highest level of CO2 storage. The injection of high volume gas into underground reservoirs contributes salt precipitation in the area around the injection well. Sine a high volume of CO2 has to be injected into underground reservoirs, at least 30 years, injectivity is an important phenomenon. Near wellbore salt precipitation due to evaporation leads to a reduction in injectivity. In this study, we investigated the effects of injection rate and salinity on injectivity due to salt precipitation. The results show that, by changing the injection rate and salinity, some interacting factors affect injectivity which determines ultimate injectivity. The final permeability analysis demonstrates salt precipitation decreases with injection rate while salinity has an opposite effect. The Peclet number analysis displays salt precipitation profile is affected by both injection rate and salinity, however, injection rate has a marked effect on injectivity. The results of this study were used to calibrate the permeability alteration model due to salt precipitation.