▎ 摘　　要

NOVELTY - Terminal amino hyperbranched polymer grafted graphene oxide plugging agent comprises graphene oxide, acrylate compound, amine compound, epichlorohydrin and cellulose. The preparation of amino hyperbranched polymer graft graphene oxide plugging agent comprises (1) mixing anhydrous methanol and amine compounds, dropwise adding mixed solution of acrylate compound and anhydrous methanol to react to obtain reaction product, and reacting to obtain amino-terminated hyperbranched polymer, (2) adding graphene oxide into distilled water, performing ultrasonically dispersing to obtain graphene oxide suspension, adding pH adjuster and amino-terminated hyperbranched polymer into graphene oxide suspension, performing ultrasonic dispersion, stirring, and (3) adding cellulose into the above obtained terminal amino hyperbranched polymer grafted graphene oxide, stirring, dropwise adding epichlorohydrin, and reacting, centrifuging, washing with ethanol and deionized water in turn, and freeze-drying. USE - The plugging agent is useful for drilling fluid (claimed). ADVANTAGE - The drilling fluid: utilizes amino-terminated hyperbranched polymer grafted graphene oxide as plugging agent with particle size of 70-1470 nm, which can effectively seal the nano-micron-sized pores in the mud shale well wall, and thus effectively stabilizes the well wall and prevent collapse; and has excellent performance in terms of rheology, stability and sealing performance under the condition of mud shale formation. DETAILED DESCRIPTION - Terminal amino hyperbranched polymer grafted graphene oxide plugging agent comprises graphene oxide, acrylate compound, amine compound, epichlorohydrin and cellulose. The preparation of amino hyperbranched polymer graft graphene oxide plugging agent comprises (1) mixing anhydrous methanol and amine compounds at 0-2℃, stirring for 10-15 minutes to obtain reaction solution, dropwise adding mixed solution of acrylate compound and anhydrous methanol into the reaction solution under nitrogen protection to react to obtain reaction product, placing the reaction product under reduced pressure at 55-65℃ for 1-2 hours, and reacting at 100-140℃ for 6-8 hours to obtain amino-terminated hyperbranched polymer, (2) adding graphene oxide into distilled water, performing ultrasonically dispersing for 30-40 minutes to obtain graphene oxide suspension, adding pH adjuster and amino-terminated hyperbranched polymer into graphene oxide suspension, performing ultrasonic dispersion for 30-40 minutes to obtain homogeneous mixture, stirring at 80-90℃ for 12-14 hours to obtain terminal amino hyperbranched polymer grafted graphene oxide, and (3) adding cellulose into terminal amino hyperbranched polymer grafted graphene oxide, stirring for 1-2 hours to obtain reaction system, dropwise adding epichlorohydrin into the reaction system, and reacting at 80-90℃ for 12-14 hours, centrifuging, washing with ethanol and deionized water in turn, and freeze-drying for 48-56 hours to obtain final product. In step (1), the mass ratio of amine compound and anhydrous methanol is 1:1-1.2, and the volume ratio of acrylate compound and anhydrous methanol is 1:1-1.2, and the mass ratio of the amine compound and the acrylate compound is 1:1-1.2, In step (2), the mass fraction of the graphene oxide dispersion liquid is 0.5-2 wt.%, and the mass ratio of the pH regulator and amino-terminated hyperbranched polymer is 1:20-30 and In step (3), the addition amount of the cellulose is 5-10 wt.% terminal amino hyperbranched polymer grafted graphene oxide, and the addition amount of the epichlorohydrin is 15-20 wt.% of terminal amino hyperbranched polymer grafted graphene oxide. An INDEPENDENT CLAIM is also included for drilling fluid i.e. oil-based drilling fluid comprising 70-90 pts. wt. white oil, 0.5-1 pt. wt. main emulsifier, 1-3 pts. wt. auxiliary emulsifier, 2-10 pts. wt. fluid loss control agent, 2-5 pts. wt. organic soil, 0.6-6.5 pts. wt. calcium oxide, 10-30 pts. wt. calcium chloride brine having concentration of 20-25 %, 0.5-2.1 pts. wt. surfactant, 10-40 pts. wt. barite, 1-10 pts. wt. amino-terminated hyperbranched polymer grafted graphene oxide plugging agent.