The use of oligoglycerol fatty acid esters, prepared from (a) an acid component chosen from (a1) fatty acids of the general formula (I) R—COOH  (I) in which R represents a saturated or unsaturated, branched or linear alkyl or alkenyl radical having 7 to 21 C atoms, and/or (a2) dicarboxylic acids and/or (a3) dimer fatty acids and/or (a4) oligomer fatty acids and/or (a5) hydroxy fatty acids with (b) a polyol component which is chosen from oligoglycerols or alkoxylates of oligoglycerols, as an additive in water-based drilling mud compositions for improving the lubricating action of these mud systems, is described.