Study On Enhancing Oil Recovery Technology For Offshore Reservoir By Foam Flooding

It is of great importance for oil production and development to carry out the research on the feasibility of foam flooding for high water cut offshore reservoir.Through the study of foam agent system,the experiment is carried out to evaluate and optimize the foaming gas,a stable foaming system with high sweeping efficiency and good foaming performance has been developed.Based on the study on the adaptability of foam flooding in the offshore reservoir,the feasibility of foam flooding to enhance oil recovery is evaluated by physical modeling and visual experiment.At the same time,the process parameters of oil extraction are optimized,and the numerical simulation method is used to study the effects of the parameters of foam flooding on enhancing oil recovery in offshore reservoir,and the parameters of foam flooding are also optimized.In this paper,through comprehensive comparing of foam properties,oil resistance,emulsifying effect,and interfacial tension,DSB-12 was optimized with better foaming performance,i.e.,when mixing with 0.1%alkali,the interfacial tension can achieve ultra-low(10^-3mN/m).The increasing of both viscosity of the foam system and strength of the liquid film were obtained by the experiment of adding several kinds of thickening polymer to improve the foam stability.Therefore,0.2%DSB-12+0.05%HPMC+0.1%NaBO₂ was selected for latter physical modelling experiments.The visualization model demonstrated that the foam had a certain low pressure,can reduce oil and water interfacial tension,increase sweeping volume,so as to enhanced oil recovery for offshore reservoir.