Experimental And Numerical Simulation Research Of CO₂ Sequestration In Aquifers Connected With Oilfield

Due to the greenhouse effect, a variety of environmental issues and ecological issues caused. CO₂ is the main greenhouse gas, so how to reduce CO₂ emissions has become a hot research in various government departments and abroad research institutions. There has three geological reservoirs suitable for CO₂ storage, it is oil reservoir, non-mined coal seams and deep saline aquifers. Although deep saline aquifers have no economic benefits generated, but it has a wide distribution, bulky, the geographical restrictions small and other advantages, therefore, in-depth study of the various factors affecting CO₂ sequestration for promote the technology of CO₂ storage has important meaning.To study the effects of various factors on CO₂ diffusion coefficient, firstly, establish a mathematical model of the diffusion coefficient, and then designed the experimental apparatus CO₂ sequestration. After analysis the experimental data, obtained different CO₂ diffusion coefficients and sequestration stock under different external conditions. Experimental results show that in a certain temperature range, the higher the temperature is, the CO₂ diffusion coefficient and dissolved gas is larger, the greater the amount of residual gas and the total storage will be; within a certain pressure range, the higher the pressure is, the CO₂ diffusion coefficient and dissolved gas is larger, the greater the amount of residual gas and the total storage will be; CO₂ Diffusion coefficient increases with the increase of the inclination angle decreases, the dissolved gas is less and the residue gas substantially constant, the total storage capacity is reduced; different filling medium clay content, the diffusion coefficient and the total storage capacity is different.Use CMG software to establish CO₂ sequestration in saline aquifers model, analysis of different factors on the proportions of various sequestrations and total buries. Research shows that the bigger the porosity is, the greater the proportion of the dissolved gas and mineral sequestration, the smaller the proportion of free gas and residual gas, porosity have a significant impact on the total number of storage capacity, the greater the porosity, the more the total amount of storage. The greater the level of penetration is, the greater the proportion of dissolved gas and minerals sequestration, the smaller the proportion of residual gas and free gas, and the amount of total sequestration is bigger. Vertical and horizontal permeability ratio also has a significant impact on the status of each sequestration, the bigger the ratio is, the proportion of dissolved gas and mineral sequestration is bigger, the proportion of residual gas and free gas is smaller, and the total sequestration capacity is bigger, the time required to reach steady sequestration is shorter. The bigger diffusion coefficient is, the greater the proportion of dissolved gas and mineral sequestration, the smaller the proportion of residual gas and free gas. The hysteresis coefficient has greater impact on the residual gas sequestration, and it has less impact on other sequestration states,.