Deep saline aquifer is a complex multi-components and multiphase flow system after CO2 injection. CO2 advection happens because of pressure gradient and velocity difference and dries out water in saline aquifer

which changes phases of the components and causes salt precipitation. The precipitated salt clogs the pore space in aquifer and decreases CO2 injectivity

so it is very important to research the effect on dry-out problem and site selection. 2D radial model is built and multiphase fluid flow function is established. By considering relative permeability function and capillary pressure function

the effects of CO2 injection rate

salty in aquifer

input maximum capillary pressure and characteristic parameters of capillary pressure on dry-out problem are studied. The dry-out problem can be quantitatively described by solid saturation. Results show that CO2 migration separates the aquifer into three domains: dry-out domain

gas and liquid mixture domain and liquid saline aquifer domain. The dry-out problem happens nearby the injection well. If capillary pressure is considered

the solid saturation will increase when injection rate decreases

salty in aquifer increases

or capillary pressure increases. As a result

increasing CO2 injection rate

injecting water into aquifer before CO2 injection

and decreasing capillary pressure by choosing a large pore size homogenous formation can avoid the clogging of pore space with salt precipitation

which enhances CO2 injectivity.