Domestic large-scale slurry circulation system manufacturing enterprises generally can design and produce cyclone desanders and slurry desilters (collectively referred to as solid control cyclones ). The core performance index of the solid control cyclone is the separation particle size, which is usually represented by D50. The lower the D50 value, the better the separation effect. In terms of quality, the wear resistance of the cyclone is of vital importance. Currently, mainstream products mostly use polyurethane or high-chromium cast iron materials to ensure a longer service life. KOSUN offers high-performance desanders and desilters engineered for optimal solids control in demanding drilling operations.
 

 
Understanding the Particle Separation Ranges

When configuring desanders and desilters, it is necessary to pay attention to the fact that the particle separation ranges of the two should not only maintain a certain interval but also have some overlap to achieve graded treatment. According to industry standards, cyclones with a separation particle size ranging from 74 to 44 μm are classified as desanders, while those with a separation particle size ranging from 44 to 15 μm are categorized as desilters.

However, in practical applications, many on-site desanders and desilters have particle sizes close to each other; for example, the desander has a particle size of 20–50 μm, and the desilter has a particle size of 45–15 μm. This results in the latter being unable to effectively remove finer solid particles when the drilling fluid treated by the desander re-enters the desilter. This issue mainly stems from the fact that the manufacturing processes of some domestic cyclones have not yet fully met the requirements of drilling techniques.
 
Common Configuration Mistakes

As a result, many users tend to replace the standard configuration of "one for sand removal and one for mud removal" with two desanders. Some users simply install a second desander at the original desilter station without adjusting the process flow. This approach is not scientific.

If the performance parameters of the two devices are the same, a more reasonable approach should be to set them as parallel processes. This can not only serve as backups for each other but also work in coordination during the rapid drilling stage to increase the processing capacity. However, for well types with high requirements for drilling fluid performance, it is still recommended to adopt the series process of "one desander + one desilter" to ensure the solid control effect.
 
Best Practices for Selection

Therefore, when choosing a desander and a desilter, models with significant differences in the range of separated particle sizes should be given priority. For instance, the desander covers 40–60 μm, while the desilter is responsible for 15–45 μm. This not only avoids the redundancy of equipment efficiency caused by overlapping processing zones but also achieves a better particle removal effect.

KOSUN's desanders and desilters are engineered with precise separation capabilities to ensure optimal performance in any drilling application.
 
Overview of Solids Control Equipment

The commonly used solid control equipment mainly includes three categories:

Drilling fluid vibrating screens – Primary solids separation

Cyclone separators – Including desanders, desilters, and mud cleaners

Drilling fluid sedimentation centrifuges – Fine solids separation and barite recovery

Among them, the cyclone separator can be further classified into desander, desilter, and mud cleaner. Drilling fluid centrifuges can be classified into screen-equipped drum centrifuges and sedimentation centrifuges based on structural differences. The former is typically used to recover the weighting materials in drilling fluid.
 
Conclusion

Proper combination of desanders and desilters in the mud circulation system is essential for efficient solids control. By selecting models with distinct particle separation ranges and configuring them correctly, either in series for high-performance wells or in parallel for increased capacity, operators can maximize solids removal efficiency, protect downstream equipment, and reduce overall drilling costs. KOSUN provides reliable desanders and desilters designed for seamless integration into any solids control system.