Preparation method of temperature-resistant and salt-resistant nano cross-linked gelled foam system for oil displacement and channeling sealing

The invention discloses a preparation method of a temperature-resistant and salt-resistant nano cross-linked gelled foam system for oil displacement and channeling sealing, relates to the technical field of foam flooding, and solves the technical problems of insufficient foam stability and unobvious acting effect on high-temperature and high-salt oil reservoirs in traditional foam flooding. Comprising the following steps: preparing an inorganic salt solution with the same mass fraction according to formation water mineralization degree data, adding an anionic surfactant, stirring until the anionic surfactant is completely dissolved, adding hydrophobic modified nano SiO2, putting the mixture into an ultrasonic cleaner, carrying out ultrasonic dispersion for 25-35 minutes, adding a polymer foam stabilizer, and stirring until the polymer foam stabilizer is completely dissolved; and sealing the beaker containing the obtained solution, and aging at the formation temperature for 72 hours. According to the present i