1) naphthenic base crude 2) naphthenic crude oil 3) naphthene base crude 4) naphthenic crude a crude oil containing less than 50% saturated hydrocarbons and over 40% naphthenic hydrocarbons GRM: n. (1,2,3,4) Note: this proportion sometimes results from the elimination of alkanes by the biodegradation of paraffinic or naphtheno-paraffinic oils References: GENcrude petroleum GENmineral naphtha GENnatural oil GENpetroleum GENraw oil GENrock oil GENfossil oil GENcrude GENcrude oil