shale shaker in drilling fluids system

High capacity drilling mud solids control equipment manufacturer- http://www.china-kosun.com/

In drilling fluids system, the first line of defense is drilling fluid shale

shaker. Shale shakers remove solids from drilling fluid as the mud passes

over the surface of a vibrating screen. Particles smaller than the openings

in the shale shaker screen pass through the holes of the screen along with

the liquid phase of the mud. Particles too large to pass through the screen

are thereby separated from the mud for disposal. Without proper

screening of the drilling fluids during this initial removal step,

downstream equipment will experience reduced efficiency and

effectiveness. The downstream desander, desilter and/or decanter

centrifuge (if employed ) will simply be overloaded beyond their design

capacity.

There are a number of commercial claims that indicate that drilling mud

shale shakers can achieve solid cuts lower than 74μm, however, when it

comes to the practical installation and use of solids control systems ( i.e.

relative to flow rates, drilling fluid viscosity, screen condition, volume of

solids being managed, etc. ) operators should conservatively assume

100μm as the performance limit.

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,

High capacity drilling mud solids control equipment manufacturer- http://www.china-kosun.com/

the quality of a shaker is defined by the quality of screens it utilizes.

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.

If the system is appropriately set up with a scalping system and a fine

shale shaker 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 fluids 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.

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.