Laboratory Experiment And Numerical Simulation Of Air Injection In Low Permeability Reservoir

Air injection for enhancing oil recovery(EOR)in low permeability reservoirs has been proved to be a very valuable technology.After air injection into reservoirs,crude oil consumes oxygen,produces carbon dioxide,carbon monoxide and other substances,releases heat at the same time,and finally crude oil is displaced by a flue gas drive.In this paper,low temperature oxidation process of crude oil has been re-recognized,and the mechanism of air injection to improve oil recovery(EOR)and low temperature oxidation(LTO)is described.Crude oil oxidation rate calculation model has been established to calculate the low-temperature oxidation reaction rate of crude oil and oxidation kinetic parameters.In this paper,the static and dynamic experiment on low temperature oxidation of crude oil is carried to research the variation of gas phase,liquid phase component and the effect of temperature,pressure,injection volume,oxygen concentration on oil displacement efficiency.Also,a one-dimensional numerical model is established to simulate the change of fluid saturation field,temperature field,gas concentration field in the process of air injection.Air displacement three-dimensional numerical simulation model is set up to study the oil displacement mechanism.Reservoir recovery efficiency at different injection ways research results show that the effect of alternating flooding of air-water flooding is better than air.Several models are set up to study the reservoir parameters such as porosity,permeability,temperature,oil saturation,analyzes its influence on oil recovery efficiency and speed,provide effective reference for air injection in the low permeability oil reservoir.Finally,the existing problems and countermeasures of air injection in oil reservoirs are analyzed,and the development direction and broad application prospect of air injection technology in the future are pointed out.