Injection And Production Parameters Optimization Of Air Flooding In Longdong Chang 7 Tight Sandstone Reservoir

Tight oil is abundant and widely distributed in Ordos basin,China.Because of the small porosity and low permeability,it is hard to inject and product by water flooding.As a low-cost gas flooding method,air flooding technology has many advantages and has been attracted in recent years.In this paper,to explore the application of air flooding in tight sandstone reservoir,the laboratory research and field application of air flooding are researched.In order to enhance oil recovery of Longdong Chang 7.There are some related studies have been done about air flooding in the tight sandstone reservoir.Firstly,the reservoir and fluid in the study block are studied.By studying on the phase characteristics of the air injection process of chang 7 tight oil,it is shown that the air in the reservoir could oxidize crude oil,and the mechanism of air flooding in the area are flue gas flooding and thermal effect.Secondly,core displacement experiments are conducted with different factors.By comparing displacement efficiency of different injection pressures,injection pressure is optimized for continuous air injection.By comparing different slug ratios,slug ratio is optimized for water alternating air.Then,on the basis of better fitting between experiment and numerical simulation,the reservoir theoretical model is used to optimize the parameters of three displacement methods.The liquid withdrawal rate,injection rate,oxygen concentration are optimized for the continuous gas injection.The cycle length and slug ratio are optimized for the cyclic air injection.The cycle length and slug number are optimized for the water alternating gas.Finally,through sensitivity analysis of injection and production parameters,well pattern model is adjusted to optimize the air flooding production program.