Abstract: A salt-tolerant polymer microsphere plugging agent and a preparation method thereof, the agent being made of white oil, fumed silica, acrylamide monomer, acrylic acid, sorbitan fatty acid ester, N,N?-methylene bisacrylamide, ammonium persulfate, sodium bisulfite, hydrophilic surfactant and water. The present general inventive concept synthesizes salt-tolerant polymer microspheres with ultra-low interfacial tension by adopting inverse phase emulsion polymerization. The prepared polymer microsphere plugging agent is a new type of polymer microspheres with ultra-low interfacial tension, such that the tension can reach 4.3×10?3 mN/m, and the salt tolerance can reach 50000 mg/L salinity, which improves the problem of low interfacial tension and poor salt tolerance in existing polymer microspheres.

Abstract: A salt-tolerant polymer microsphere plugging agent and a preparation method thereof, the agent being made of white oil, fumed silica, acrylamide monomer, acrylic acid, sorbitan fatty acid ester, N,N?-methylene bisacrylamide, ammonium persulfate, sodium bisulfite, hydrophilic surfactant and water. The present general inventive concept synthesizes salt-tolerant polymer microspheres with ultra-low interfacial tension by adopting inverse phase emulsion polymerization. The prepared polymer microsphere plugging agent is a new type of polymer microspheres with ultra-low interfacial tension, such that the tension can reach 4.3×10?3 mN/m, and the salt tolerance can reach 50000 mg/L salinity, which improves the problem of low interfacial tension and poor salt tolerance in existing polymer microspheres.

Abstract: Disclosed are a pH-responsive amphoteric surfactant N-lauryl-(?-alkyl)-?-aminopropionic acid and a preparation method and uses thereof. An alkylamine and a solvent are added to a three-necked flask, stirred for complete dissolution, slowly dropwise added with methyl ?-alkyl-acrylate and reacted at room temperature after the ice-water bath is removed. The reaction mixture is refluxed in water bath and evaporated under rotation to remove the solvent and the residual methyl ?-alkyl-acrylate to give N-lauryl-(?-alkyl)-?-aminopropionic acid. Then N-lauryl-(?-alkyl)-?-aminopropionic acid and water are added to a three-necked flask, slowly dropwise added with a sodium hydroxide solution and reacted in water bath to give a crude product, which is filtered and dried to give a purified surfactant sodium N-lauryl-(?-alkyl)-?-aminopropionate. This surfactant is suitable for the foamed acid system and its performance can be switched by adjusting pH due to pH sensitivity.

Abstract: Disclosed are a pH-responsive amphoteric surfactant N-lauryl-(?-alkyl)-?-aminopropionic acid and a preparation method and uses thereof. An alkylamine and a solvent are added to a three-necked flask, stirred for complete dissolution, slowly dropwise added with methyl ?-alkyl-acrylate and reacted at room temperature after the ice-water bath is removed. The reaction mixture is refluxed in water bath and evaporated under rotation to remove the solvent and the residual methyl ?-alkyl-acrylateto give N-lauryl-(?-alkyl)-?-aminopropionic acid. Then N-lauryl-(?-alkyl)-?-aminopropionic acid and water are added to a three-necked flask, slowly dropwise added with a sodium hydroxide solution and reacted in water bath to give a crude product, which is filtered and dried to give a purified surfactant sodium N-lauryl-(?-alkyl)-?-aminopropionate. This surfactant is suitable for the foamed acid system and its performance can be switched by adjusting pH due to pH sensitivity.