The processes of flooding—water flooding, polymer flooding and ternary combination flooding—were simulated respectively on a 2-D positive rhythm profile geological model by using the ASP numerical modeling softw...The processes of flooding—water flooding, polymer flooding and ternary combination flooding—were simulated respectively on a 2-D positive rhythm profile geological model by using the ASP numerical modeling software developed by RIPED (Yuan, et al. 1995). The recovery coefficient, remaining oil saturation, sweep efficiency and displacement efficiency were calculated and correlated layer by layer. The results show that the sweep efficiency and displacement efficiency work different effects on different layers in the severely heterogeneous reservoir. The study shows that the displacement efficiency and sweep efficiency play different roles in different layers for severely heterogeneous reservoirs. The displacement efficiency contributes mainly to the high permeability zones, the sweep efficiency to the low permeability zones, both of which contribute to the middle permeable zones. To improve the sweep efficiency in the low permeability zones is of significance for enhancing the whole recovery of the reservoir. It is an important path for improving the effectiveness of chemical flooding in the severely heterogeneous reservoirs to inject ternary combination slug after profile control.展开更多
CO2 flooding is a process whereby carbon dioxide is injected into an oil reservoir in order to increase output when extracting oil. Since 1952, Wharton obtained the patent concern CO2 flooding, CO2-EOR （CO2 flooding ...CO2 flooding is a process whereby carbon dioxide is injected into an oil reservoir in order to increase output when extracting oil. Since 1952, Wharton obtained the patent concern CO2 flooding, CO2-EOR （CO2 flooding enhance oil recovery） has been one of research hot-spot around the world. According to the statistical data of 2006, there are total of 94 global CO2-EOR projects, including 65 low permeability oilfield projects （79% of the total）. Daqing Oilfield is the largest one of China, after more than 50 years of continuous development, oilfield comprehensive water cut has reached over 90%, and the difficulty of oilfield development has been gradually increasing. In recent years, low and ultra-low permeability reservoirs development have played a more and more important role accompany with low permeability reserves in proportion of the total reserves have been increasing year by year. But water-flooding recovery of low permeability reservoir is very low under the influence of reservoir poor properties and heterogeneity. As a kind of greenhouse gas, CO2 flooding can obtain good results for the low permeability reservoir in which the water flooding has proven ineffective. CO2 flooding Pilot Test was conducted under such background since Dec. 2002, over 10 years of practice has proved that CO2 flooding is an effective method to improve the development effect of low permeability reservoir, all experience during the mechanism study and field test should present important references for further larger-scale CO2 flooding projects.展开更多
基金This project is supported by the China National Key Basis Research Project (No: G1999022512)
文摘The processes of flooding—water flooding, polymer flooding and ternary combination flooding—were simulated respectively on a 2-D positive rhythm profile geological model by using the ASP numerical modeling software developed by RIPED (Yuan, et al. 1995). The recovery coefficient, remaining oil saturation, sweep efficiency and displacement efficiency were calculated and correlated layer by layer. The results show that the sweep efficiency and displacement efficiency work different effects on different layers in the severely heterogeneous reservoir. The study shows that the displacement efficiency and sweep efficiency play different roles in different layers for severely heterogeneous reservoirs. The displacement efficiency contributes mainly to the high permeability zones, the sweep efficiency to the low permeability zones, both of which contribute to the middle permeable zones. To improve the sweep efficiency in the low permeability zones is of significance for enhancing the whole recovery of the reservoir. It is an important path for improving the effectiveness of chemical flooding in the severely heterogeneous reservoirs to inject ternary combination slug after profile control.
文摘CO2 flooding is a process whereby carbon dioxide is injected into an oil reservoir in order to increase output when extracting oil. Since 1952, Wharton obtained the patent concern CO2 flooding, CO2-EOR （CO2 flooding enhance oil recovery） has been one of research hot-spot around the world. According to the statistical data of 2006, there are total of 94 global CO2-EOR projects, including 65 low permeability oilfield projects （79% of the total）. Daqing Oilfield is the largest one of China, after more than 50 years of continuous development, oilfield comprehensive water cut has reached over 90%, and the difficulty of oilfield development has been gradually increasing. In recent years, low and ultra-low permeability reservoirs development have played a more and more important role accompany with low permeability reserves in proportion of the total reserves have been increasing year by year. But water-flooding recovery of low permeability reservoir is very low under the influence of reservoir poor properties and heterogeneity. As a kind of greenhouse gas, CO2 flooding can obtain good results for the low permeability reservoir in which the water flooding has proven ineffective. CO2 flooding Pilot Test was conducted under such background since Dec. 2002, over 10 years of practice has proved that CO2 flooding is an effective method to improve the development effect of low permeability reservoir, all experience during the mechanism study and field test should present important references for further larger-scale CO2 flooding projects.
