Preparation of branched epoxy resin pressure-bearing plugging material and oil-based drilling fluid

The invention discloses a preparation method of a branched epoxy resin pressure-bearing plugging material and an oil-based drilling fluid, the pressure-bearing plugging material has a branched structure, and is characterized in that the material comprises the following raw materials: vinyl naphthalene, vinyl benzene, multi-benzene-ring nitrile, hexagonal boron nitride and a silane coupling agent, the silane coupling agent is (3, 4-dichlorophenyl)-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4-trimethyl-1, 3, 4- the molar ratio of the vinyl naphthalenes to the vinyl benzenes to the multi-benzene ring nitrile is 1: (1-3): (3-4). According to the synthesized branched epoxy resin polymer, modified hexagonal boron nitride with hydroxyl and carboxyl on the surface is combined through a silane coupling agent, the pressure bearing capacity of the final product branched epoxy resin pressure-bearing plugging material can reach 150-18