Due to the low permeability and small pore throat of low permeability tight reservoirs,conven-tional enhanced oil recovery methods are difficult to effectively displace crude oil from low permeability reservoirs.A nano-imbibition displacement agent was synthesized by using surfactant and nano-Al2O3 par-ticles,and core imbibition and displacement experiments were carried out by optimizing its stability,static evaluation of interfacial tension and wettability,so as to study the imbibition and displacement effect of nano-oil displacement agent in low-permeability core.The results show that the wettability of rock wall can be changed by nano-Al2O3 imbibition displacement agent,and the wettability angle can be changed by 57.5%.Effectively reduce the interfacial tension,reducing it to 70%;for low permeability core,it has good imbibition recovery effect,and the imbibition recovery effect can reach 37%at 60℃.In the dis-placement experiment,the oil recovery rate increased by 16%with the nano displacement agent.
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