Preparation method of gemini hybrid fluorine surfactant applied as shale fracturing fluid cleanup additive

Abstract

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.

Description

1. Technical field [0001] The invention relates to a preparation method of a shale fracturing fluid drainage aid gemini hybrid fluorosurfactant. This fluorine-containing surfactant can also be used as a sandstone fracturing fluid drainage aid and as a flooding aid in tertiary oil recovery technology. The oil agent belongs to the fields of organic chemistry, surface and interface chemistry, fracturing and enhanced oil and gas recovery. 2. Background technology [0002] Shale gas is an unconventional natural gas resource, which occurs in organic-rich shale-based reservoir rock series. my country may have the world's largest technically recoverable reserves of shale gas, about 26×10 12 m 3 , with US 24.4 x 10 12 m 3 resources are comparable. Sichuan is the most abundant area of ​​shale gas in my country, with recoverable resources of about 4.42×10 12 m 3 , accounting for 17.7% of my country's total, is expected to become China's largest shale gas production base, however,...

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Problems solved by technology

[0004] The purpose of the present invention is to aim at the poor salt resistance of fluorine-containing active agents currently used as shale fracturing fluid drainage aids, poor ability to reduce oil-water interfacial tension, and high dosage. The wetting contact angle of the surface has a small increase and other shortcomings, providing a high-salt resistance, which can significantly increase the water phase wetting contact angle of the rock surface, and has low surface and interfacial tension, which can be used for shale fracturing The preparation method of the gemini hybridized fluorosurfactant of the liquid drainage aid is characterized in that the first synthetic raw material is an alkylene oxide, and the alkylene oxide is 1, 2, (n+2), (n+3) -Diepoxide alkylene, integer n=2~18 (see attachment for molecular structure figure 1 ), at least one of 2-perfluoroalkylethanol C m f 2m+1 CH 2 CH 2 OH, at least one of the integers m=4 to 18 is the second synthetic raw material, at least one of the sodium haloalkylsulfonate is the third synthetic raw material, and the sodium haloalkylsulfonate is sodium chloroalkylsulfonate Cl(CH 2 ) x SO 3 Na, integer x=2~8, sodium bromoalkylsulfonate Br(CH 2 ) x SO 3 Na, integer x=2~8, sodium iodoalkylsulfonate I(CH 2 ) x SO 3 Na, at least one of integer x=2~8, represented by sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), sodium hydride (NaH), potassium hydride (KH), calcium hydride ( CaH 2 ), sodium hydroxide (NaOH), potassium hydroxide (KOH), potassium carbonate (K 2 CO 3 ), sodium carbonate (Na 2 CO 3 ), potassium bicarbonate (KHCO 3 ) and sodium bicarbonate (NaHCO 3 ) is a catalyst, and at least one of tetrahydrofuran, N,N-dimethylformamide, dichloromethane, chloroform, ethyl acetate, 1,4-dioxane and cyclohexane The species is used as a solvent, and a gemini hybrid fluorosurfactant C grafted with 2 fluorocarbon chains and 2 sulfonate ions on a hydrocarbon chain was synthesized. m f 2m+1 CH 2 CH 2 O-CH 2 CH(O(CH 2 ) x SO 3 Na)-(CH 2 ) n - CH(O(CH 2 ) x SO 3 Na)-CH 2 -OCH 2 CH 2 C m f 2m+1 , integer m=4~18, integer n=2~18, integer x=2~8 (molecular structure see attached figure 1 ), this Gemini hybrid fluorosurfactant is referred to as GHF

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