Preparation and Performance Study of Microemulsions Composed of Anion-Nonionic Surfactants

Because of special physical and chemical properties of microemulsion, it has become one of the research hotspots of oil and gas exploitation as an important production enhancement aid. In this paper, an anionic nonionic surfactant (polyfatty alcohol polyoxyethylene ether acrylate sodium stylenesulfonate lauryl acrylate, P(AEO-9-AA-SSS-LA)) was prepared and mixed with cosurfactant, produced water and crude oil to obtain a new type of middle phase microemulsion. The structure of P(AEO-9-AA-SSS-LA) was characterized by infrared spectrum and nuclear magnetic hydrogen spectrum, and the particle size, interfacial tension, salt resistance, emulsion stability, temperature resistance and static adsorption capacity of the middle phase microemulsion were tested. The results show that the average particle size of the droplets of the middle phase microemulsion is about 25 nm, and the droplets are connected to each other in an orderly manner. The interfacial tension reaches 10−2mN/m, and the adsorption capacity of 0.01 wt% middle phase microemulsion after 24 h of adsorption in the oil sands is about 9 mg/g. In addition, the prepared middle phase microemulsion has excellent temperature and salt resistance, which is expected to be used in the field of tertiary oil recovery.