دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a soft. black, shiny mineral of pure carbon produced when hydrocarbons are subjected to high temperahires and pressures. Used in pencils and crucibles, as a lubricant. and in atomic-energy plants to control the release of radiation from uranium fuel.

n: A mud additive for lowering torque (rotary friction) and drag (axial friction) in the wellbore and to lubricate bit bearings if not sealed. Lubricants may be solids, such as plastic beads, glass beads, nut hulls and graphite, or liquids, such as oils, syn

materials that reduce torque and drag. May be oil, synthetic (polymer) liquids, graphite, glycols, glycerines, etc.