Well drilling solids control hydrocyclones

Hydrocyclones also refer to cyclones or cones. In well drilling solids control there are desander and desilter utilized different size of hydrocyclone.

Hydrocyclones introduction

Hydrocyclones are simple mechanical devices, with out moving parts, designed to speed up the settling process. Feed pressure is transformed into centrifugal force inside the cyclone or cone to accelerate particle settling in accordance with Stoke’s Law #1. In essence, a cyclone is a miniature settling pit which alloys very rapid settling of solids under controlled conditions.

Hydrocyclones desilter

Hydrocyclones desilter

Hydrocyclones have become important in solid control systems because of their ability to efficiently remove particles smaller than the finest mesh screens. They are also uncomplicated devices, which make them easy to use and maintain

Solids control hydrocyclone

A hydrocyclone consist of a conical shell with a small opening at the bottom for the underflow discharge, a larger opening at the top for liquid discharge through an internal “vortex finder”  and a feed nozzle on the side of the body near the wide (top) end of the cone.

Drilling mud enters the cyclone under pressure from a centrifugal feed pump. The velocity of the mud causes the particles to rotate rapidly within the main chamber of the cyclone. Light, fine solids and the liquid phase of the mud tend to spiral inward and upward for discharge through the liquid outlet. Heavy, coarse solids and the liquid film around them tend to spiral outward and downward for discharge through the solid outlet or under flow.

Design features of cyclones units vary widely according to the size.  The cyclones are made of composite materials and hold up to wear quite well. The size of cyclones in use varies from 12” down to 2”. The measurement refers to the inside diameter of the largest, cylinders section of the cyclone. In general, but not always, the larger the cone, the larger the cut point and the greater the thru put.

Desander and desilter hydrocyclone

In solids control system, desander is installed downstream from shaker. Desander will generally get rid of cuttings larger than 74 microns. While desilter will separate solids larger than 15 microns. Desander cones diameter are always larger than 5″, Desilter will be 4″ or 5″.

Both desander and desilter should be able to process 100%~125% of total mud circulation rate. Kindly suggest all users use separated pump for desander and desilter. But, many clients prefer combination of desander, desilter and shaker for space-save and higher efficient.


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