Research on oil recovery technology of surfactant flooding assisted by low frequency resonance wave

Aiming at the problems of low water displacement recovery and poor development effect in low permeability reservoir of Fengfuchuan in Shanbei, a new oil recovery technique of surfactant flooding assisted by low frequency resonance wave is proposed in this paper. The oil extraction, emulsification, adsorption of surfactant under low frequency vibration wave and application effect are evaluated by laboratory experiments combined with field application. The indoor experiments results show that under low frequency vibration wave, oil extraction efficiency can improve about 2.5%; meanwhile, the increase of self emulsifying ability makes the average droplet size of emulsion become smaller and uniform distributed, and it also reduces both the coalescing velocity of emulsion liquid and separating water rate resulting in dynamic stability being enhanced. Adsorption isothermal of surfactant falls dramatically accompanied by adsorption capacity reduce. The reservoir field test results show the water cut is reduced by 15% or more with average oil increase of about 40% for single well. Successful application of the composite technology provides some guidance in low permeability reservoirs for increasing oil production, controlling water and improving water flooding recovery.