Shaker screen field experience information

Shaker screen field experience

On the basis of shaker screen field experience from oilfield, running a coarse scalping screen over a very fine primary screen has been practiced for a long time. The majority of the 171⁄2-in. sections have been drilled with a screen configuration consisting of a 10-mesh scalping screen over lower-deck primary screens ranging from 200-mesh to 300-mesh. Rectangular and square cloths have sometimes been used. In such cases, the shaker- screen consumption, or wear, has been extremely high. Only 1.2 m3 of drilled formation solids has been removed per screen used.

Shaker screen field experience

Shaker screen field experience

The overall shaker-screen consumption, based on information from the drilling-fluid and shaker-screen suppliers and supported by internal data, shows that an average of 2.7 m3 of drilled for- mation solids has been removed per used screen. This is with a “trash limit” of 20% “damaged” cloth. Here damaged means either damaged or repaired with plugs or sealing compound.

Screening area for solids control optimization

Optimized solids control implies that more than 50% of the screening area can be blanked off and the screen can still have sufficient filtration ability as long as total-flow capacity is sufficient to handle the well flow. Field experience demonstrates that removal of 800 to 1000 m3 of drilled formation solids is readily achievable before a screen needs to be disposed of, even if a more restrictive trash limit is used.

shaker screen API size

shaker screen API size

Good work practice, which also removes exposure to drilling- fluid dampness and mist, includes changing all the screens on a shaker with a different batch of screens at regular inspection intervals. These screens are then investigated, the damages are re- paired, and these screens are changed back into the shakers at next inspection. In this way, work time at the shaker is reduced, interference with the drilling operation is minimized, and shaker-screen maintenance is optimized.

As described in the screen opening and mesh sizes section, the mesh definition is the number of wires per 1 in. of a cloth. Therefore the cut point will be influenced by the wire diameter and does not follow the same scale as the different mesh sizes do.

Shaker screen open areas for each mesh size do not follow the same scale as the mesh description does. Using mesh as an exact definition of a filtration quality for a cloth is not sufficient and can be confusing for the daily handling on the rigs. Cut point and the particle sizes where 16 and 84% of the particles go through the screen are actually the parameters necessary to optimize solids control.

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