Screening surface in solids control

Screening surface used in solids control equipment including the shale shaker screen and mud cleaner bottom screen. What is the appropriate system employed proper screen?

Screening surface

Screening surface is the shaker screen. Basically, a screen acts as a “go/no-go” gauge: Either a particle is small enough to pass through the screen or it is not. Screening surfaces used in solids control equipment are generally made of multi-layered woven wire screen cloth and are the “heart and soul” of the shaker. Fundamentally, the quality of a shaker is defined by the quality of screens it utilized. When selecting a solids control system it is important that the quality of the screen manufacturing and level of experience by the in manufacturing screens is considered.

Screening surface in solids control

Screen system configuration

If the system is appropriately set up with a scalping system and a fine screen system, the scalping screens must be sized just coarse enough to ensure that drilling fluid does not sheet off the shaker (i.e. whole mud losses). This happens when the scalping screen is too fine to allow the drilling fluid to pass into the solids control system’s dirty tank.

Typical scalping screen configurations for HDD applications range from 50 mesh (API 50) to 120 mesh (API 100). Typical fine screen configurations range from 160 (API 120) to 200 mesh (API 170). The API 13C classification is gaining traction in the HDD industry as more contractors focus on the micron cut point they are trying to achieve in their fluid.

Shaker screen opening

Relative to the use of shaker screens, it is the size of the screen openings, not the mesh count that determines the size of the particles separated by the screen. It is because of this fact that HDD system users should compare and specify screens based on their API 13C designation.