Modified graphite-coated soft particle and method for preparing same, and profile control and water shutoff agent and application thereof

A modified graphite-coated soft particle, comprising a soft particle and first modified graphite coating on a surface of the soft particle, wherein the soft particle comprises a rubber main agent, an antioxidant, an auxiliary antioxidant, a density regulator, and second modified graphite, and the first modified graphite and the second modified graphite are the same or different and each are modified graphite with a surface rich in hydroxyl groups and carboxyl groups;

• wherein a particle size of the modified graphite is 200 nm-1000 nm, a thickness of the first modified graphite coating on the surface of the soft particle is 30 nm-50 μm, and a particle size of the modified graphite-coated soft particle is 200 μm-3.5 mm;
• wherein the modified graphite contains oxygen-containing groups, the oxygen-containing groups comprise hydroxyl groups, carboxyl groups, and epoxy groups, and based on a total number of the oxygen-containing groups of the modified graphite, the number of the hydroxyl groups accounts for 30%-60%, the number of the carboxyl groups accounts for 10%-30%, and the number of the epoxy groups accounts for 30%-40%;
• wherein based on a total weight of the soft particle, a content of the rubber main agent is 65 wt %-85 wt %, a content of the antioxidant is 0.1 wt %-0.5 wt %, a content of the auxiliary antioxidant is 0.05 wt %-0.3 wt %, a content of the second modified graphite is 5 wt %-10 wt %, and a content of the density regulator is 4 wt %-30 wt %;
• and
• wherein the modified graphite-coated soft particle is formed by a method comprising mixing the first modified graphite and water to obtain a first modified graphite dispersion, the first modified graphite dispersion having a concentration of 0.1%-1%;
• bringing the first modified graphite dispersion and the soft particle into contact, wherein a weight ratio of the amount of the first modified graphite dispersion to the amount of the soft particle is 100:(2-20);
• and causing the first modified graphite to adhere to the surface of the soft particle under conditions of heating and rotation.