Performance improvement of CO 2 flooding using production controls in 3D areal heterogeneous models: Experimental and numerical simulations

CO2 flooding is a promising technology used to enhance oil recovery as it increases oil production and sequesters CO2 in low permeability oil reservoirs. However, the areal heterogeneity of a reservoir can seriously affect CO2 flooding efficiency. The importance of production control treatments (sweeping area regulation, differential production pressure control, and real-time producing regulation) are thus proposed to improve the performance of CO2 flooding in areal heterogeneous reservoirs. Three dimensional (3D) physical models and core-scale numerical models with areal heterogeneity and 5-spot patterns are designed using dimensionless scaling groups. Conventional CO2 flooding and CO2 production control flooding are conducted successively in the 3D models, and flooding efficiency is evaluated through oil recovery increments and changes in the displacement pressure drop curves. Mechanisms of CO2 performance improvement using production control treatments are also discussed through the analytical analysis of gas distribution and gas/oil mobility ratio.