If uncased boreholes are to be drilled in loose rock, the use of additives is state of the art. When drilling in predominantly clayey sediments, PAA or CMC polymers are recommended as sole additives. For uniform mixing of these drilling muds, mud hoppers are uses. Mud hoppers are powered by the mud system’s centrifugal pump on the drilling rig. They flow the mud at high velocity through a venturi nozzle. Through a hopper above the nozzle solid additives are put into the circulating mud system.
The Venturi process is an often used technique for enriching liquids with solids. The Venturi effect is named after Giovanni Battista Venturi, an Italian physicist.
