The effects of dissolved Sodium Chloride (NaCl) on well injectivity during CO2 storage into saline aquifers

Saline aquifer formations seem to be promising candidates for carbon dioxide (CO2) storage due to their wide availability as well they have large storage capacity. Once CO2 is injected into saline aquifer variety of processes will take place, among of them is the formation dry out and salt precipitation phenomenon, the main driver of this phenomenon is the salinity in the form of Halite (NaCL), this considers a major challenge of CO2 injection into saline aquifers, it causes the risk of formation clogging and will effect on the well injectivity and lead to pressure build up. The selected candidate for carbon dioxide (CO2) storage should meet the technical requirements of sealing integrity, storage capacity (potential) and containment. After the commencement of carbon dioxide (CO2) injection into high salinity formations, formation dry out due to salt precipitation in the near wellbore will take place and this cause permeability and injectivity reduction. This work will focuses on experimental work. The experimental work investigations studied the effectiveness dilution of high sodium chloride NaCl solutions with sea water and its contribution in improving the injectivity. After saturating the sandstone core samples with different brine solutions, linear core flow tests using nitrogen gas (N2) were carried out. The saturated samples in diluted solutions for castlegate sandstone sample showed increase in the flow rate from 4 L/min at 50 psi to 5 L/min at the same pressure, experimentally it was confirmed that dilution of brine solutions by seawater will assist in improving the sandstone core samples porosity , permeability and the injectivity. Keywords- CO2 storage, seawater, CO2/Brine/Rock, Salinity, porosity, permeability CO2 injectiviy