Solid Control system Screen Separation Equipment

• Apr 22, 2022
• Solid control is an important mechanical process to keep the drilling fluids in their optimum parameters to perform operations safely and effectively. ...

Solid control is an important mechanical process to keep the drilling fluids in their optimum parameters to perform operations safely and effectively. 

 

 

The solid control can be classified according to the applied method as follows: 

- Screen separation using for example shale shakers 

- Settling separation in sand traps and settling mud pits 

- Gas separation inside the degassers and surface vacuum 

- Forced separation by applying a centrifugal force in desanders, desilters and centrifuges. 

 

Screen Separation 

The shale shaker is a screen device and it contains one or more vibrating screens which mud passes through. During operations, mud comes out from the well through the flow line to the mud box, then the mud is distributed to the vibrating shale shakers. Normally, the mud pass through the screens and the drill cuttings are segregated out of the drilling fluids system. If the shakers work effectively and screens are the correct type and size, up to 80% of drill cuttings can be separated. 

 

According to the vibration motion, the shakers are categorized in two types: elliptical and linear motion. Related to the oil field experience, it seems that the elliptical shakers are suitable for water based mud and linear motion shakers are more effective for oil based mud. 

There are some rig recommendations for optimized operations which can be summarized as follows: 

Three shale shakers is recommended for normal operations to allow quick and simple screens replacements. 

Screen sizes should be chosen to separate maximum solids without affecting mud components, or overloading the shakers which can lead to mud surface losses. 

Drilling fluids, when passing over the screens, should not exceed two third (2/3) of the total screens lengths to avoid surface losses and also to permit the conveying of dry solids toward shakers exit. 

If the screen blinding is faced, reducing the flow rate can be a solution without affecting the hole cleaning. 

In order to keep the screen and shakers in good shape and to avoid the premature damage, never run the shale shakers dry.