▎ 摘　　要

NOVELTY - Drilling fluid comprises: an organic or aqueous base; at least one weighting material in particulate form having a density of 2 g/cm3, preferably 4 g/cm3 and present in liquid suspension with the base; and graphene. USE - The fluid is useful for drilling underground rock formations (claimed) and oil wells. ADVANTAGE - The fluid allows easy drilling of underground rock formations, can be prepared in an economical manner, and replaces organic thickeners with graphene thus improving the drilling process in conditions of high temperature and high pressure. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) preparing the drilling fluid, comprising diluting a masterbatch free of organic polymer comprising graphene and oil in the organic or aqueous base, the weighting agent, optionally the surfactant and/or the thickening agent; (2) a master batch present in the form of granules, comprising graphene and oil; and (3) preparing the masterbatch, comprising: introducing and kneading the graphene and the oil in a compounding device to obtain a composite, extruding and cooling the composite to obtain a master batch in solid form, and shaping the masterbatch to obtain granules.