Desanders and desilters are drilling rig equipment with a set of hydrocyclones that separates sand and silt from the drilling fluid. Desander is installed after shakers and degasser but before desilter. Desander removes those abrassive solids from the drilling mud which cannot be removed by shakers. Desilting is employed in dams and lakes.
Desander for solids control
Desander have no moving parts. The larger the internal diameter of the desander is, the greater the amount of drilling fluids it is able to process and the larger the size of the solids removed. Desander (10 inches (250 mm) cone) are able to remove 50% of solids within the 40-50 μm (micrometre) range at a flow rate of 500 US gallons per minute (32 L/s), while desilter (4 inches (100 mm) Cone) are able to remove 50% of solids within the 15-20 μm range at a flow rate of 60 US gallons per minute (3.8 L/s). Micro fine separators are able to remove 50% of solids within the 10-15 μm range at a flow rate of 15 US gallons per minute (0.95 L/s). Desander is typically positioned next-to-last in the arrangement of solids control equipment, with decanter centrifuge as the subsequent processing unit. Desander are preceded by gas busters, gumbo removal equipment (if utilized), shale shaker, mud cleaner (if utilized) and vacuum degasser. Desander is widely used in oilfield drilling.