Research On Migration And Diffusion Behaviors Of CO₂in Saline Aquifers

China’s energy resources situation indicate that it’s rich in coal,but lack in oil and gas，so in the future coal will still remain energy source for a long period of time. It is a barrier tothe implementation of low carbon economy development in our country but the industry cannot slow down the economic development in order to reduce carbon emissions.We should take initiative measures to slow down or avoid hazards and disasters due togreenhouse gases. As development of structural traps is common in saline aquifers so these aresuitable for CO2storage. In deep aquifers as water salinity is higher can’t take advantage ofseveral important characteristics. Therefore, strengthening experimental study trappingmechanisms of CO2in saline aquifers can provide a scientific basis for large-scale CO2salineaquifer sequestration. Therefore,if we can determine the CO2migration diffusion coefficientand its main influencing factors in saline aquifers.It will provide important reference data forCO2scale sequestration in saline aquifers.To explore the diffusion migration law of CO2in brine and promote the scale sequestrationof CO2in saline aquifers,we do experimental study for CO2in saline aquifers. For measuringthe diffusion properties of CO2in the brine under different conditions,we design andmanufacture diffusion experimental setup. Through laboratory experiments and analysis,we getthe diffusion coefficient and study the temperature,injection pressure, different salinity andother factors which impact the diffusion coefficient of CO2.Experimental results show that under the single variable experimental conditions,as thetemperature increases,the diffusion coefficient and migration coefficient of CO2increases; thediffusion coefficient and migration coefficient of CO2gradually decreases as the pressureincreases,the increase in the diffusion coefficient of CO2migration coefficient,but when thepressure increased to a certain extent,the pressure on the diffusion coefficient will become smaller and smaller. The diffusion coefficient and migration coefficient of CO2graduallydecreases with the increase of salinity. At different saline aquifer conditions,the diffusioncoefficient of CO2is significantly different.But the migration coefficient is not significantly.