The technology of water plugging in the oil well is more and more concerned with its low cost, low damage and long period of validity. But in the application, it is found that the effect of water shutoff and profile control of active crude oil in different blocks is quite different. Plugging measures effect is obvious in some fields, while in the others, it is very poor. The reason is that the content of gum and asphaltene in crude oil components of different blocks is quite different, and this substance will have a great influence on the emulsification effect of active crude oil. In order to improve the level of active⁃crude⁃oil water plugging technology fundamentally, on the basis of extensive investigation and research, the influence factors of emulsifier structures and crude oil composition on oil⁃in⁃water emulsion are studied, through the laboratory emulsification experiment and spectral analysis. It is concluded that the longer the length of the oil⁃wet carbon⁃carbon single chain of the Span series of emulsifier, the greater the viscosity of the emulsion. The existence of double bond is not conducive to the formation of emulsion and the emulsion viscosity is low. The composition of 5 aromatic rings in the gum is conducive to the dissolution of asphaltenes, while the planar arrangement of 5 aromatic rings will increase the viscosity of the emulsion.

A cardanol phenolformaldehyde resin was synthesized using cardanol and formaldehyde as raw material, and the cardanol based phenolformaldehyde resin block polyether demulsifier (CPFE) was further synthesized using cardanol phenolformaldehyde resin as initiator through polymerization with epoxy propane (PO) and epoxyethane (EO), respectively. The crtical micelle concentration of CPFE was measured with the method of surface tension, and the results showed that the crtical micelle concentration of CPFE was 80 mg/L and the γcmc was 17.38 mN/m. The oilwater interfacial tension of CPFE was determined with a spinning drop tension meter. The influences of concentration and temperature on oilwater interfacial tensions were discussed in detail. Experimental results showed that the oilwater interfacial tension dereased obviously with the increase of concentration of CPFE, and the interfacial activity of CPFE dedined as temperature increased, which illustrated that the CPFE could be applied in low temperature environment. The oil droplet rupture constant k was measured by single droplet method, and the oil droplet rupture constant k increased with the increase of CPFE concentration. 