The invention discloses a preparation method of a gemini
hybrid fluorine surfactant applied as a shale
fracturing fluid cleanup additive. The preparation method is characterized by comprising the following steps: adding 10-200 parts by weight of a
solvent and 0.5-8 parts by weight of a catalyst into a three-mouth reaction
bottle provided with a
reflux condensing device, dropwise adding a solution containing 20-200 parts by weight of a
solvent and 10 parts by weight of 2-perfluoroalkyl
ethanol in an ice bath under the condition of introducing
nitrogen, carrying out stirring and reacting for 4 hours, then conducting heating to 45-95 DEG C, slowly and dropwise adding a solution containing 20-200 parts of a
solvent and 0.5-10 parts of diepoxyalkane, carrying out reacting for 10-36 hours, then gradually and dropwise adding a solution containing 10-250 parts of a solvent and 3-15 parts of halogenated
alkyl sodium sulfonate into the three-mouth reaction
bottle, continuing reacting for 24-72 hours, maintaining the
reaction temperature within 45-95 DEG C, carrying out reduced-pressure
distillation on a
reaction product to remove the solvent so as to obtain a crude product, and then carrying out
silica gel column chromatography separation to obtain the gemini
hybrid fluorine surfactant with yield of 60-90%. The
fluorine surfactant can obviously reduce the
capillary pressure of shale.