Crude oil demulsifier is an oil field chemical agent for oil-water separation of petroleum production fluid. Its demulsification principle is that the demulsifier penetrates deeply and adheres to the interface of the emulsified droplets, replaces the original emulsifier and destroys the surface film, and coats the film. The droplets are released and coalesced, so that the oil and water phases are separated. Because the oil extraction technology does not change from the initial water injection to thermal recovery of heavy oil, to alkaline water flooding, surfactant flooding, polymer flooding and tertiary oil recovery, the colloids, asphalt, naphthenic acid in crude oil The emulsification of, fatty acid and salt, crystalline paraffin, and artificially introduced various surface-active substances makes the extracted crude oil present the form of emulsion. In addition, due to the continuous advancement of new technologies, most of the current oil fields in my country have entered a period of high water cut. The crude oil emulsion has changed from CDE type to EDC type. The demulsification mechanism and other aspects have also undergone great changes. For an ideal crude oil demulsifier, it should have strong surface activity, good wetting performance, sufficient flocculation ability, and better coalescence effect. While meeting the needs of oilfields and ensuring the demulsification and dehydration effect of crude oil, it has also greatly promoted the development of crude oil demulsifiers.Crude oil demulsifier is an oil field chemical agent for oil-water separation of petroleum production fluid. Its demulsification principle is that the demulsifier penetrates deeply and adheres to the interface of the emulsified droplets, replaces the original emulsifier and destroys the surface film, and coats the film. The droplets are released and coalesced, so that the oil and water phases are separated. Because the oil extraction technology does not change from the initial water injection to thermal recovery of heavy oil, to alkaline water flooding, surfactant flooding, polymer flooding and tertiary oil recovery, the colloids, asphalt, naphthenic acid in crude oil The emulsification of, fatty acid and salt, crystalline paraffin, and artificially introduced various surface-active substances makes the extracted crude oil present the form of emulsion. In addition, due to the continuous advancement of new technologies, most of the current oil fields in my country have entered a period of high water cut. The crude oil emulsion has changed from CDE type to EDC type. The demulsification mechanism and other aspects have also undergone great changes. For an ideal crude oil demulsifier, it should have strong surface activity, good wetting performance, sufficient flocculation ability, and better coalescence effect. While meeting the needs of oilfields and ensuring the demulsification and dehydration effect of crude oil, it has also greatly promoted the development of crude oil demulsifiers.