In the oil and gas industry, a desander is a piece of equipment used in the solids control process during drilling operations. Its main purpose is to remove larger solid particles, typically ranging from 40 to 100 microns, from the drilling fluid or mud.
During drilling, the drilling fluid or mud is circulated down the drill string and back up the wellbore. This fluid carries cuttings, rock fragments, and other solid particles to the surface. It is important to separate these solid particles from the drilling fluid to maintain its properties and effectiveness.
A desander is typically part of a larger solids control system that includes equipment such as shale shakers, desilters, and centrifuges. The desander unit consists of a set of hydrocyclones, similar to the ones used in a desilter, but designed to remove larger particles.
The drilling fluid enters the desander unit, and the hydrocyclones create a swirling flow, causing the heavier particles to settle towards the wall of the hydrocyclone. These larger particles are then discharged through an underflow nozzle. The drilling fluid, with fewer solid particles, flows towards the center of the hydrocyclone and exits through an overflow nozzle. This process effectively removes the larger solid particles from the drilling fluid.
By removing the larger particles, desanders help to maintain the properties of the drilling fluid, such as its density, viscosity, and filtration properties. This is crucial for efficient drilling operations, as it helps prevent equipment damage, improves drilling performance, and ensures the proper disposal of the solid particles.
In summary, desanders are essential components of the solids control process in the oil and gas industry. They are used to remove larger solid particles from the drilling fluid, contributing to the overall efficiency and success of drilling operations.