What are drilling muds?
During the drilling of a well, drilling fluids or “muds” are used to lubricate and cool the drill bit, control reservoir pressure, and transport the drill cuttings back to the surface. Drilling discharges are made up of drilling muds that have not stayed in the borehole and cuttings, the crushed rock from the borehole. Three general types of drilling muds have been used during drilling operations: water-based drilling muds, oil-based drilling muds, and synthetic-based drilling muds. Water-based drilling fluids or muds (WBF or WBM) are used at some stage during all well drilling. The primary components of WBM are fresh or salt water, barite, clay, caustic soda, lignite, lignosulfonates, and water soluble polymers. The specific composition depends on the type of formation (i.e., layers of rocks sharing common properties) being drilled. WBM and WBM-wetted cuttings may be discharged. Oil-based drilling fluids or muds (OBF or OBM) are used to improve drilling through difficult formations. T
