▎ 摘　　要

NOVELTY - Water-based wellbore fluid comprises aqueous base fluid and modified graphene shale inhibitor that comprises one or more substituents that are covalently bonded to graphene via linking group. The one or more substituents is hydrocarbon group that has number of carbon atoms in the range from 8-14. USE - Water-based wellbore fluid. ADVANTAGE - The water-based wellbore fluid improves shale inhibition capacity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: a method for drilling wellbore, which involves circulating water-based drilling mud into the wellbore while drilling, water-based drilling mud comprises modified graphene shale inhibitor that comprises one or more substituents that are covalently bonding to graphene via a linking group, and one or more substituents is hydrocarbon group that contains number of carbon atoms in the range from 8-14; and#a method for preparing modified graphene shale inhibitor, which involves preparing carboxylic acid-containing graphene oxide by oxidizing graphite, reacting the carboxylic acid-containing graphene oxide with halogenating agent to give an acyl halide-containing graphene and reacting the acyl halide-containing graphene with a substituent-bearing compound to give the modified graphene shale inhibitor, substituent-bearing compound contains hydrocarbon chain and one or more functional groups selected from carboxylic acids, alcohols, aldehydes, amines, amides, glycols, and silanes.