Experimental and theoretical investigations of CO₂ injectivity.
Yen Sokama-Neuyam, Jann Ursin
Vol. 33, no. 2 (2016), s. 245-257, [1]
Laboratory sandstone core flooding experiments were conducted to investigate the impact of brine desaturation and salt precipitation on CO₂ injectivity. An attempt was then made to reduce the impact of salt precipitation on CO2 injectivity by injecting a slug of diluent prior to CO₂ injection. The effect of brine salinity, CO2 injection rate and initial core permeability on the efficacy of this mitigation technique was investigated. Decrease in diluent brine salinity improved injectivity but there exist a critical brine salinity below which CO₂ injectivity was further impaired. It was also observed that, above a certain CO₂ injection rate, alternating CO₂ injection with the diluent brine could not enhance CO₂ injectivity. Injectivity improvement also depends on initial permeability of the porous medium. Up to about 30% injectivity improvement was observed in the experiments.