Synthesis of a New Type of Gemini Surfactants and Study on the Repair Performance of Near-Well Reservoir

In this paper, a new type of Gemini surfactant was synthesized by esterification reaction of phthalic anhydride and fatty alcohol polyoxyethylene ether to improve the pollution problem and achieve the purpose of reservoir restoration in the near-wellbore area. The target product was characterized by infrared spectroscopy and hydrogen nuclear magnetic resonance spectroscopy. The ability of Gemini surfactant to reduce boundary surface tension, wettability, dispersion, viscosity reduction, oil washing and core damage recovery were studied. Gemini surfactant The critical micelle concentration (cmc) and the corresponding γ-cmc of Gemini surfactant are 26 mg/L and 30.26 μN/m, respectively. Gemini surfactant has a good ability to wash oil, which effectively reduce the interfacial tension of oil and water. At the same time, the benzene ring in the molecular structure of Gemini surfactant dissolve the organic matter in the pollution source, and the core permeability could be restored.