Ultralow-temperature nano silicon oxide dispersion system as well as preparation method and application thereof

The invention belongs to the technical field of drilling fluid, and particularly relates to an ultralow-temperature nano silicon oxide dispersion system as well as a preparation method and application thereof. The invention provides a preparation method of an ultralow-temperature nano silicon oxide dispersion system, which comprises the following steps: mixing a nano silicon oxide particle suspension and a nonionic surfactant for the first time, and carrying out a dehydration reaction to obtain modified nano silicon oxide particles; the nonionic surfactant is prepared from one or more of fatty alcohol-polyoxyethylene ether, fatty alcohol polyoxypropylene polyoxyethylene ether, iso-tridecanol polyoxyethylene ether and cocamidopropyl polyoxyethylene ether, and the nonionic surfactant is prepared from one or more of fatty alcohol-polyoxyethylene ether, fatty alcohol polyoxypropylene polyoxyethylene ether, iso-tridecanol polyoxyethylene ether and cocamidopropyl polyoxyethylene ether; and mixing the modified nano