Mud circulation in the hole Photo courtesy the Power Institute Circulation program - pumps drilling mud (combination of water, clay, weighting materials and chemical compounds, accustomed to carry rock cuttings through the drill bit on the floor) under pressure from the kelly, rotary desk, drill pipes and drill collars First https://arthurjcrfs.slypage.com/20714468/5-simple-statements-about-oil-rig-explained